CAUT

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Chris.  I'm sorry, but how does lowering the pitch slightly to reduce tension going to help? It won't be enough to prevent string breakage and the piano will be out of tune. 

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

For the path of a least resistance strategy. To lower tension and the breaking percent. It would be good to measure the current tension and Bp%. Maybe the allowable safety margin for tension and Bp% are maxed and a hard blow tips it over. Would tuning a couple cents lower hurt? After that its surgery on the capo and re-scaling. Also hammers can be voiced to be bright and not be rocks. 

-chris

Chris.  I'm sorry, but how does lowering the pitch slightly to reduce tension going to help? It won't be enough to prevent string breakage and the piano will be out of tune. 

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Not seeing the laugh emoji after Chris's pitch suggestion.  Yes, it's only jazz... maybe we can encourage them to  use Verdi pitch?

The part about the hardened capo is probably right, but not easily addressed without the range of measures Floyd Gadd is describing... in shop setting.

The  moniters positioned behind the pianist might work, in theory, but points to a much larger problem... the classic one for large ensemble musicians, especially amplified, but not only.  What are the other players doing to protect their hearing?  Can we determine the veracity of the theory that pianists do, in these settings, 'play-up' to where they can hear themselves?   If all the measures (de-hardening the capo, restringing with Paullelo, etc.) were taken, you may reduce the string breakage, but all the other conditions - playing to be heard - would persist.   Perhaps brighter (without harder) hammers with increased let-off would help.  Still, the existential dilemma for these guys is that they're supposed to be learning ensemble playing.  Do they want/need to rely on the sound-guy to make it work?  Might as well be in a booth with headphones.

The tonal improvements that Floyd cites don't appear to be the relevant target here.  If Wim noted that newly replaced strings were breaking, that would be a 'thing', but what if a straight forward restringing significantly reduced breakage?

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

David  Thanks for your sage advice. I want to restring the upper sections, and dress the capo, to see if that keeps the strings from breaking. But I almost don't want that to solve the problem because I want to show the head of the department that the problem isn't the piano, but the way it is being played. As I said the jazz piano professor has a very heave touch, and she teaches her students to play the same way. I've basically told her that, but of course she doesn't think she's the problems. She's actually alluded to blaming me for the problem, citing that strings were not breaking with the previous tuner.  

Not seeing the laugh emoji after Chris's pitch suggestion.  Yes, it's only jazz... maybe we can encourage them to  use Verdi pitch?

The part about the hardened capo is probably right, but not easily addressed without the range of measures Floyd Gadd is describing... in shop setting.

The  moniters positioned behind the pianist might work, in theory, but points to a much larger problem... the classic one for large ensemble musicians, especially amplified, but not only.  What are the other players doing to protect their hearing?  Can we determine the veracity of the theory that pianists do, in these settings, 'play-up' to where they can hear themselves?   If all the measures (de-hardening the capo, restringing with Paullelo, etc.) were taken, you may reduce the string breakage, but all the other conditions - playing to be heard - would persist.   Perhaps brighter (without harder) hammers with increased let-off would help.  Still, the existential dilemma for these guys is that they're supposed to be learning ensemble playing.  Do they want/need to rely on the sound-guy to make it work?  Might as well be in a booth with headphones.

The tonal improvements that Floyd cites don't appear to be the relevant target here.  If Wim noted that newly replaced strings were breaking, that would be a 'thing', but what if a straight forward restringing significantly reduced breakage?

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

David  Thanks for your sage advice. I want to restring the upper sections, and dress the capo, to see if that keeps the strings from breaking. But I almost don't want that to solve the problem because I want to show the head of the department that the problem isn't the piano, but the way it is being played. As I said the jazz piano professor has a very heave touch, and she teaches her students to play the same way. I've basically told her that, but of course she doesn't think she's the problems. She's actually alluded to blaming me for the problem, citing that strings were not breaking with the previous tuner.  

Not seeing the laugh emoji after Chris's pitch suggestion.  Yes, it's only jazz... maybe we can encourage them to  use Verdi pitch?

The part about the hardened capo is probably right, but not easily addressed without the range of measures Floyd Gadd is describing... in shop setting.

The  moniters positioned behind the pianist might work, in theory, but points to a much larger problem... the classic one for large ensemble musicians, especially amplified, but not only.  What are the other players doing to protect their hearing?  Can we determine the veracity of the theory that pianists do, in these settings, 'play-up' to where they can hear themselves?   If all the measures (de-hardening the capo, restringing with Paullelo, etc.) were taken, you may reduce the string breakage, but all the other conditions - playing to be heard - would persist.   Perhaps brighter (without harder) hammers with increased let-off would help.  Still, the existential dilemma for these guys is that they're supposed to be learning ensemble playing.  Do they want/need to rely on the sound-guy to make it work?  Might as well be in a booth with headphones.

The tonal improvements that Floyd cites don't appear to be the relevant target here.  If Wim noted that newly replaced strings were breaking, that would be a 'thing', but what if a straight forward restringing significantly reduced breakage?

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

David  Thanks for your sage advice. I want to restring the upper sections, and dress the capo, to see if that keeps the strings from breaking. But I almost don't want that to solve the problem because I want to show the head of the department that the problem isn't the piano, but the way it is being played. As I said the jazz piano professor has a very heave touch, and she teaches her students to play the same way. I've basically told her that, but of course she doesn't think she's the problems. She's actually alluded to blaming me for the problem, citing that strings were not breaking with the previous tuner.  

Not seeing the laugh emoji after Chris's pitch suggestion.  Yes, it's only jazz... maybe we can encourage them to  use Verdi pitch?

The part about the hardened capo is probably right, but not easily addressed without the range of measures Floyd Gadd is describing... in shop setting.

The  moniters positioned behind the pianist might work, in theory, but points to a much larger problem... the classic one for large ensemble musicians, especially amplified, but not only.  What are the other players doing to protect their hearing?  Can we determine the veracity of the theory that pianists do, in these settings, 'play-up' to where they can hear themselves?   If all the measures (de-hardening the capo, restringing with Paullelo, etc.) were taken, you may reduce the string breakage, but all the other conditions - playing to be heard - would persist.   Perhaps brighter (without harder) hammers with increased let-off would help.  Still, the existential dilemma for these guys is that they're supposed to be learning ensemble playing.  Do they want/need to rely on the sound-guy to make it work?  Might as well be in a booth with headphones.

The tonal improvements that Floyd cites don't appear to be the relevant target here.  If Wim noted that newly replaced strings were breaking, that would be a 'thing', but what if a straight forward restringing significantly reduced breakage?

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

I seem to remember hearing somewhere that a normal timeframe for rebuilding a non-concert grand is somewhere between the 50 and 75 year mark, but for a grand that's used in a concert / performance situation where there's very heavy use, the timeframe is more like 10-20 years. It seems like the piano in question has exceeded the expected lifespan of the latter category and is ready to be rebuilt or replaced. 

David  Thanks for your sage advice. I want to restring the upper sections, and dress the capo, to see if that keeps the strings from breaking. But I almost don't want that to solve the problem because I want to show the head of the department that the problem isn't the piano, but the way it is being played. As I said the jazz piano professor has a very heave touch, and she teaches her students to play the same way. I've basically told her that, but of course she doesn't think she's the problems. She's actually alluded to blaming me for the problem, citing that strings were not breaking with the previous tuner.  

Not seeing the laugh emoji after Chris's pitch suggestion.  Yes, it's only jazz... maybe we can encourage them to  use Verdi pitch?

The part about the hardened capo is probably right, but not easily addressed without the range of measures Floyd Gadd is describing... in shop setting.

The  moniters positioned behind the pianist might work, in theory, but points to a much larger problem... the classic one for large ensemble musicians, especially amplified, but not only.  What are the other players doing to protect their hearing?  Can we determine the veracity of the theory that pianists do, in these settings, 'play-up' to where they can hear themselves?   If all the measures (de-hardening the capo, restringing with Paullelo, etc.) were taken, you may reduce the string breakage, but all the other conditions - playing to be heard - would persist.   Perhaps brighter (without harder) hammers with increased let-off would help.  Still, the existential dilemma for these guys is that they're supposed to be learning ensemble playing.  Do they want/need to rely on the sound-guy to make it work?  Might as well be in a booth with headphones.

The tonal improvements that Floyd cites don't appear to be the relevant target here.  If Wim noted that newly replaced strings were breaking, that would be a 'thing', but what if a straight forward restringing significantly reduced breakage?

The Capos are too hardened, perhaps you can lower the pitch slightly to reduce tension.

-chris

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

William -

Trying to process this:

• the coil - I'm not clear what you're describing, nor the significance of the 'deformation' at this location.  Unless I missed it, the breakage is taking place at the capo.  Where is the plastic deformation and how does that effect an increased propensity for breakage?
• the characteristics of concern with regard to the capo seem to be:
  • degree of hardness
  • profile of v-bar
  • friction
• your focus seems to be on the latter.  I'm not sure I grasp the mechanics of that friction as a primary cause of breakage.

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Fair enough, David.  I think I need to connect the dots a little more completely.

Rereading the posts, I am not seeing that the breakage is occurring at the capo bar.  I certainly have seen that in high use pianos such as are being described in this thread.  But it is far more common for the break to occur at the coil by a huge margin, so I am going to assume that is the case with Wim's piano.  

Let's count the strikes that have already been identified.  Played hard 20 hours a week for 20 years.  It would not be surprising for the hammers to flattened with long grooves AND the hammers are very hard.  This alone is bad for string fatigue, but getting them to file the hammers is likely to fall on deaf ears, as is getting all the McCoy Tyner wannabees to let up.  Piano wire is elastic, and under tension its whole life in a piano.  Even if the piano is not played at all, the wire will creep as its life continues.  Add this incredible amount of time and hard abuse, and that process of creep will accelerate dramatically. String breakage in this environment is common and well-known by technicians.

It is common for all pianos to have the breaking percentages going up, up, up as we ascend the scale.  Which is to say for these ever thinning wires that the start point after stringing is closer to the breaking point.  The string has less far to travel before it gives up the ghost.  We should also understand that during heavy playing the breaking percentage in a manner of speaking is increasing - indeed, it can spike past the breaking point in terms of the load on the string from the hard blow, ever so briefly.  When this is occurring, this dramatically accelerates metal fatigue in the string cumulatively.  

How many of us have been tuning and raising the pitch on a particular string and come to a point where the pitch is no longer going up as we move the hammer, and then POP, the string breaks, usually at the coil?  The wire has moved past its elastic limit into the realm of dramatic plastic deformation where the string stretches and thins and breaks.  

I am going to start to connect this to friction - what does friction have to do with the string breaking at the coil and not at the V bar?  (Most of the time).  What we need to understand is that the string bearing against the V bar is not static.  When the string oscillates, it is sliding back and forth along its length on the bearing surface, hundreds or thousands of times per second.  The contact surface for the string to bear on is very small, so the pressures from even a string tensioned at 160 lbs, is enormous, on the order of 200,000 psi!  That is enough to deform the surface of bridge pins, which might be in the range of 60,000 psi before plastic deformation occurs.  Cast iron falls well below that, even with a well dressed capo bar.  

Let me introduce the notion of stick/slip. The string, as part of its oscillation always has sticking friction, where it binds against the plate and then releases, it sticks and then slips with every single oscillation. The string is literally being abraded by the softer iron, and the iron contacting surface is being deformed into the ever elongating string impressions which further increase the frictional load because of more contacting surface.  

Yeah, but the cap surface is several inches away from the tuning pin, so that should not make a difference, right?  

When the string sticks, tension builds in the wire on one side of the contacting surface because it is binding on deformities in the surface called asperities (think of the deformity as a dam).  The string tension always wants to move into equilibrium with the lower tensions on the other side of the contact patch.  The building tension becomes overwhelming and the stick is released and slips across the patch, and the tension equilibrates.  Moreover, the tension along the length of the string is always moving in and out of equilibrium, so the inequalities of tension at the capo bar are acting on the string at the pin.  

The string is already much closer to plastic deformation because the bend is so tight.  The outside edge of the string is under very high tension, while the inner edge of the string which bears against the surface is under compression, and there is a transition tension/compression zone between them.  The spikes in tension from heavy blows are felt at the tuning pin and are further weakening the string at its most vulnerable place.  And now we can add stiction that may also exist at the string rest felts behind the front duplexes.  

So what does the incredibly smooth frictional surface that I am recommending have to do with the cost of tulips in Holland?  Simply put, it dramatically reduces the build-up of tension before the string renders.  If we have removed the grooves and have a well-shaped termination, then the formation of new asperities is dramatically decreased.  Couple this with XM wire, and you will have a hugely improved service life.

i would flip the piano over upside down on blankets to dress the V bar and polish it.

William -

Trying to process this:

• the coil - I'm not clear what you're describing, nor the significance of the 'deformation' at this location.  Unless I missed it, the breakage is taking place at the capo.  Where is the plastic deformation and how does that effect an increased propensity for breakage?
• the characteristics of concern with regard to the capo seem to be:
  • degree of hardness
  • profile of v-bar
  • friction
• your focus seems to be on the latter.  I'm not sure I grasp the mechanics of that friction as a primary cause of breakage.

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

I have kept a respectable distance from this thread while absorbing the details of various opinions and statements about Wims' C7 capo-bar string breakage. I feel some technicians are spot on while others make folkloric statements without any backup research. This thread has conjured up some pretty bizarre statements.

Fair enough, David.  I think I need to connect the dots a little more completely.

Rereading the posts, I am not seeing that the breakage is occurring at the capo bar.  I certainly have seen that in high use pianos such as are being described in this thread.  But it is far more common for the break to occur at the coil by a huge margin, so I am going to assume that is the case with Wim's piano.  

Let's count the strikes that have already been identified.  Played hard 20 hours a week for 20 years.  It would not be surprising for the hammers to flattened with long grooves AND the hammers are very hard.  This alone is bad for string fatigue, but getting them to file the hammers is likely to fall on deaf ears, as is getting all the McCoy Tyner wannabees to let up.  Piano wire is elastic, and under tension its whole life in a piano.  Even if the piano is not played at all, the wire will creep as its life continues.  Add this incredible amount of time and hard abuse, and that process of creep will accelerate dramatically. String breakage in this environment is common and well-known by technicians.

It is common for all pianos to have the breaking percentages going up, up, up as we ascend the scale.  Which is to say for these ever thinning wires that the start point after stringing is closer to the breaking point.  The string has less far to travel before it gives up the ghost.  We should also understand that during heavy playing the breaking percentage in a manner of speaking is increasing - indeed, it can spike past the breaking point in terms of the load on the string from the hard blow, ever so briefly.  When this is occurring, this dramatically accelerates metal fatigue in the string cumulatively.  

How many of us have been tuning and raising the pitch on a particular string and come to a point where the pitch is no longer going up as we move the hammer, and then POP, the string breaks, usually at the coil?  The wire has moved past its elastic limit into the realm of dramatic plastic deformation where the string stretches and thins and breaks.  

I am going to start to connect this to friction - what does friction have to do with the string breaking at the coil and not at the V bar?  (Most of the time).  What we need to understand is that the string bearing against the V bar is not static.  When the string oscillates, it is sliding back and forth along its length on the bearing surface, hundreds or thousands of times per second.  The contact surface for the string to bear on is very small, so the pressures from even a string tensioned at 160 lbs, is enormous, on the order of 200,000 psi!  That is enough to deform the surface of bridge pins, which might be in the range of 60,000 psi before plastic deformation occurs.  Cast iron falls well below that, even with a well dressed capo bar.  

Let me introduce the notion of stick/slip. The string, as part of its oscillation always has sticking friction, where it binds against the plate and then releases, it sticks and then slips with every single oscillation. The string is literally being abraded by the softer iron, and the iron contacting surface is being deformed into the ever elongating string impressions which further increase the frictional load because of more contacting surface.  

Yeah, but the cap surface is several inches away from the tuning pin, so that should not make a difference, right?  

When the string sticks, tension builds in the wire on one side of the contacting surface because it is binding on deformities in the surface called asperities (think of the deformity as a dam).  The string tension always wants to move into equilibrium with the lower tensions on the other side of the contact patch.  The building tension becomes overwhelming and the stick is released and slips across the patch, and the tension equilibrates.  Moreover, the tension along the length of the string is always moving in and out of equilibrium, so the inequalities of tension at the capo bar are acting on the string at the pin.  

The string is already much closer to plastic deformation because the bend is so tight.  The outside edge of the string is under very high tension, while the inner edge of the string which bears against the surface is under compression, and there is a transition tension/compression zone between them.  The spikes in tension from heavy blows are felt at the tuning pin and are further weakening the string at its most vulnerable place.  And now we can add stiction that may also exist at the string rest felts behind the front duplexes.  

So what does the incredibly smooth frictional surface that I am recommending have to do with the cost of tulips in Holland?  Simply put, it dramatically reduces the build-up of tension before the string renders.  If we have removed the grooves and have a well-shaped termination, then the formation of new asperities is dramatically decreased.  Couple this with XM wire, and you will have a hugely improved service life.

i would flip the piano over upside down on blankets to dress the V bar and polish it.

William -

Trying to process this:

• the coil - I'm not clear what you're describing, nor the significance of the 'deformation' at this location.  Unless I missed it, the breakage is taking place at the capo.  Where is the plastic deformation and how does that effect an increased propensity for breakage?
• the characteristics of concern with regard to the capo seem to be:
  • degree of hardness
  • profile of v-bar
  • friction
• your focus seems to be on the latter.  I'm not sure I grasp the mechanics of that friction as a primary cause of breakage.

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Roger, if you want to disagree with me in this thread, i welcome your commentary.  After all this forum also serves as an arena for ideas, does it not?  I know I am swimming upstream against what may be the conventional wisdom, so if you think I am in error, please share your thoughts.

However, standing on the sidelines and throwing impolitic bombs with no substance and only the aspersions, makes you sound like a crank.

I have kept a respectable distance from this thread while absorbing the details of various opinions and statements about Wims' C7 capo-bar string breakage. I feel some technicians are spot on while others make folkloric statements without any backup research. This thread has conjured up some pretty bizarre statements.

Fair enough, David.  I think I need to connect the dots a little more completely.

Rereading the posts, I am not seeing that the breakage is occurring at the capo bar.  I certainly have seen that in high use pianos such as are being described in this thread.  But it is far more common for the break to occur at the coil by a huge margin, so I am going to assume that is the case with Wim's piano.  

Let's count the strikes that have already been identified.  Played hard 20 hours a week for 20 years.  It would not be surprising for the hammers to flattened with long grooves AND the hammers are very hard.  This alone is bad for string fatigue, but getting them to file the hammers is likely to fall on deaf ears, as is getting all the McCoy Tyner wannabees to let up.  Piano wire is elastic, and under tension its whole life in a piano.  Even if the piano is not played at all, the wire will creep as its life continues.  Add this incredible amount of time and hard abuse, and that process of creep will accelerate dramatically. String breakage in this environment is common and well-known by technicians.

It is common for all pianos to have the breaking percentages going up, up, up as we ascend the scale.  Which is to say for these ever thinning wires that the start point after stringing is closer to the breaking point.  The string has less far to travel before it gives up the ghost.  We should also understand that during heavy playing the breaking percentage in a manner of speaking is increasing - indeed, it can spike past the breaking point in terms of the load on the string from the hard blow, ever so briefly.  When this is occurring, this dramatically accelerates metal fatigue in the string cumulatively.  

How many of us have been tuning and raising the pitch on a particular string and come to a point where the pitch is no longer going up as we move the hammer, and then POP, the string breaks, usually at the coil?  The wire has moved past its elastic limit into the realm of dramatic plastic deformation where the string stretches and thins and breaks.  

I am going to start to connect this to friction - what does friction have to do with the string breaking at the coil and not at the V bar?  (Most of the time).  What we need to understand is that the string bearing against the V bar is not static.  When the string oscillates, it is sliding back and forth along its length on the bearing surface, hundreds or thousands of times per second.  The contact surface for the string to bear on is very small, so the pressures from even a string tensioned at 160 lbs, is enormous, on the order of 200,000 psi!  That is enough to deform the surface of bridge pins, which might be in the range of 60,000 psi before plastic deformation occurs.  Cast iron falls well below that, even with a well dressed capo bar.  

Let me introduce the notion of stick/slip. The string, as part of its oscillation always has sticking friction, where it binds against the plate and then releases, it sticks and then slips with every single oscillation. The string is literally being abraded by the softer iron, and the iron contacting surface is being deformed into the ever elongating string impressions which further increase the frictional load because of more contacting surface.  

Yeah, but the cap surface is several inches away from the tuning pin, so that should not make a difference, right?  

When the string sticks, tension builds in the wire on one side of the contacting surface because it is binding on deformities in the surface called asperities (think of the deformity as a dam).  The string tension always wants to move into equilibrium with the lower tensions on the other side of the contact patch.  The building tension becomes overwhelming and the stick is released and slips across the patch, and the tension equilibrates.  Moreover, the tension along the length of the string is always moving in and out of equilibrium, so the inequalities of tension at the capo bar are acting on the string at the pin.  

The string is already much closer to plastic deformation because the bend is so tight.  The outside edge of the string is under very high tension, while the inner edge of the string which bears against the surface is under compression, and there is a transition tension/compression zone between them.  The spikes in tension from heavy blows are felt at the tuning pin and are further weakening the string at its most vulnerable place.  And now we can add stiction that may also exist at the string rest felts behind the front duplexes.  

So what does the incredibly smooth frictional surface that I am recommending have to do with the cost of tulips in Holland?  Simply put, it dramatically reduces the build-up of tension before the string renders.  If we have removed the grooves and have a well-shaped termination, then the formation of new asperities is dramatically decreased.  Couple this with XM wire, and you will have a hugely improved service life.

i would flip the piano over upside down on blankets to dress the V bar and polish it.

William -

Trying to process this:

• the coil - I'm not clear what you're describing, nor the significance of the 'deformation' at this location.  Unless I missed it, the breakage is taking place at the capo.  Where is the plastic deformation and how does that effect an increased propensity for breakage?
• the characteristics of concern with regard to the capo seem to be:
  • degree of hardness
  • profile of v-bar
  • friction
• your focus seems to be on the latter.  I'm not sure I grasp the mechanics of that friction as a primary cause of breakage.

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

William,

Did I disagree with you? Call me a crank if that pleases you, I'm thick skinned.

Roger

Roger, if you want to disagree with me in this thread, i welcome your commentary.  After all this forum also serves as an arena for ideas, does it not?  I know I am swimming upstream against what may be the conventional wisdom, so if you think I am in error, please share your thoughts.

However, standing on the sidelines and throwing impolitic bombs with no substance and only the aspersions, makes you sound like a crank.

I have kept a respectable distance from this thread while absorbing the details of various opinions and statements about Wims' C7 capo-bar string breakage. I feel some technicians are spot on while others make folkloric statements without any backup research. This thread has conjured up some pretty bizarre statements.

Fair enough, David.  I think I need to connect the dots a little more completely.

Rereading the posts, I am not seeing that the breakage is occurring at the capo bar.  I certainly have seen that in high use pianos such as are being described in this thread.  But it is far more common for the break to occur at the coil by a huge margin, so I am going to assume that is the case with Wim's piano.  

Let's count the strikes that have already been identified.  Played hard 20 hours a week for 20 years.  It would not be surprising for the hammers to flattened with long grooves AND the hammers are very hard.  This alone is bad for string fatigue, but getting them to file the hammers is likely to fall on deaf ears, as is getting all the McCoy Tyner wannabees to let up.  Piano wire is elastic, and under tension its whole life in a piano.  Even if the piano is not played at all, the wire will creep as its life continues.  Add this incredible amount of time and hard abuse, and that process of creep will accelerate dramatically. String breakage in this environment is common and well-known by technicians.

It is common for all pianos to have the breaking percentages going up, up, up as we ascend the scale.  Which is to say for these ever thinning wires that the start point after stringing is closer to the breaking point.  The string has less far to travel before it gives up the ghost.  We should also understand that during heavy playing the breaking percentage in a manner of speaking is increasing - indeed, it can spike past the breaking point in terms of the load on the string from the hard blow, ever so briefly.  When this is occurring, this dramatically accelerates metal fatigue in the string cumulatively.  

How many of us have been tuning and raising the pitch on a particular string and come to a point where the pitch is no longer going up as we move the hammer, and then POP, the string breaks, usually at the coil?  The wire has moved past its elastic limit into the realm of dramatic plastic deformation where the string stretches and thins and breaks.  

I am going to start to connect this to friction - what does friction have to do with the string breaking at the coil and not at the V bar?  (Most of the time).  What we need to understand is that the string bearing against the V bar is not static.  When the string oscillates, it is sliding back and forth along its length on the bearing surface, hundreds or thousands of times per second.  The contact surface for the string to bear on is very small, so the pressures from even a string tensioned at 160 lbs, is enormous, on the order of 200,000 psi!  That is enough to deform the surface of bridge pins, which might be in the range of 60,000 psi before plastic deformation occurs.  Cast iron falls well below that, even with a well dressed capo bar.  

Let me introduce the notion of stick/slip. The string, as part of its oscillation always has sticking friction, where it binds against the plate and then releases, it sticks and then slips with every single oscillation. The string is literally being abraded by the softer iron, and the iron contacting surface is being deformed into the ever elongating string impressions which further increase the frictional load because of more contacting surface.  

Yeah, but the cap surface is several inches away from the tuning pin, so that should not make a difference, right?  

When the string sticks, tension builds in the wire on one side of the contacting surface because it is binding on deformities in the surface called asperities (think of the deformity as a dam).  The string tension always wants to move into equilibrium with the lower tensions on the other side of the contact patch.  The building tension becomes overwhelming and the stick is released and slips across the patch, and the tension equilibrates.  Moreover, the tension along the length of the string is always moving in and out of equilibrium, so the inequalities of tension at the capo bar are acting on the string at the pin.  

The string is already much closer to plastic deformation because the bend is so tight.  The outside edge of the string is under very high tension, while the inner edge of the string which bears against the surface is under compression, and there is a transition tension/compression zone between them.  The spikes in tension from heavy blows are felt at the tuning pin and are further weakening the string at its most vulnerable place.  And now we can add stiction that may also exist at the string rest felts behind the front duplexes.  

So what does the incredibly smooth frictional surface that I am recommending have to do with the cost of tulips in Holland?  Simply put, it dramatically reduces the build-up of tension before the string renders.  If we have removed the grooves and have a well-shaped termination, then the formation of new asperities is dramatically decreased.  Couple this with XM wire, and you will have a hugely improved service life.

i would flip the piano over upside down on blankets to dress the V bar and polish it.

William -

Trying to process this:

• the coil - I'm not clear what you're describing, nor the significance of the 'deformation' at this location.  Unless I missed it, the breakage is taking place at the capo.  Where is the plastic deformation and how does that effect an increased propensity for breakage?
• the characteristics of concern with regard to the capo seem to be:
  • degree of hardness
  • profile of v-bar
  • friction
• your focus seems to be on the latter.  I'm not sure I grasp the mechanics of that friction as a primary cause of breakage.

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

William, can you please post where you purchased the Tungsten Disulfide Nano-powder. Thanks!

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Will,

Point of clarification: did you intend to recommend polishing with grits up to 12,000, as written, or 1200?

Thanks,

Alan

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Alan, I would take it up to 12,000 in progressive grits before the WS2 treatments.  So i will ask you a question - why do you think I would go to these lengths?  What do you think my reasoning behind that would be?

Will,

Point of clarification: did you intend to recommend polishing with grits up to 12,000, as written, or 1200?

Thanks,

Alan

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

William,

I think you go up to 12,000 grit because it makes a noticeable, positive difference. It is just that I had not heard of that previously, and wanted to make sure that I understood it correctly. I don't own any 12,000 grit sandpaper, but you can be sure that that is about to change.

I have not seen your work, but your posts indicate that you are someone with deep knowledge and high standards, which is why I speak of you only with great respect to others.

Best,

Alan

Alan, I would take it up to 12,000 in progressive grits before the WS2 treatments.  So i will ask you a question - why do you think I would go to these lengths?  What do you think my reasoning behind that would be?

Will,

Point of clarification: did you intend to recommend polishing with grits up to 12,000, as written, or 1200?

Thanks,

Alan

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Those kinds of papers do exist, and they can go much higher in grits, over 100,000 grit.  These are grits directed more towards optical finishing and such.  I have been studying terminations for a while, and it has become an ongoing subject with deep interest to me.  Recently, i have been obsessing about friction at terminations such as bridge pins, something that strangely enough, not much attention beyond the superficial has been given. It is as if everyone thinks that high degrees of friction are a necessary evil to secure the string to the pin and bridge surface and we must endure the unavoidable wear and deterioration that comes with that.  I am not convinced that this is the case, or the best choice.  I have slowly come to the belief that materials with a very low COF may be better and more durable, and with positive tonal benefits

William,

I think you go up to 12,000 grit because it makes a noticeable, positive difference. It is just that I had not heard of that previously, and wanted to make sure that I understood it correctly. I don't own any 12,000 grit sandpaper, but you can be sure that that is about to change.

I have not seen your work, but your posts indicate that you are someone with deep knowledge and high standards, which is why I speak of you only with great respect to others.

Best,

Alan

Alan, I would take it up to 12,000 in progressive grits before the WS2 treatments.  So i will ask you a question - why do you think I would go to these lengths?  What do you think my reasoning behind that would be?

Will,

Point of clarification: did you intend to recommend polishing with grits up to 12,000, as written, or 1200?

Thanks,

Alan

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Those kinds of papers do exist, and they can go much higher in grits, over 100,000 grit.  These are grits directed more towards optical finishing and such.  I have been studying terminations for a while, and it has become an ongoing subject with deep interest to me.  Recently, i have been obsessing about friction at terminations such as bridge pins, something that strangely enough, not much attention beyond the superficial has been given. It is as if everyone thinks that high degrees of friction are a necessary evil to secure the string to the pin and bridge surface and we must endure the unavoidable wear and deterioration that comes with that.  I am not convinced that this is the case, or the best choice.  I have slowly come to the belief that materials with a very low COF may be better and more durable, and with positive tonal benefits

William,

I think you go up to 12,000 grit because it makes a noticeable, positive difference. It is just that I had not heard of that previously, and wanted to make sure that I understood it correctly. I don't own any 12,000 grit sandpaper, but you can be sure that that is about to change.

I have not seen your work, but your posts indicate that you are someone with deep knowledge and high standards, which is why I speak of you only with great respect to others.

Best,

Alan

Alan, I would take it up to 12,000 in progressive grits before the WS2 treatments.  So i will ask you a question - why do you think I would go to these lengths?  What do you think my reasoning behind that would be?

Will,

Point of clarification: did you intend to recommend polishing with grits up to 12,000, as written, or 1200?

Thanks,

Alan

Ken, I think it is likely safe to simply replace the strings using XM wire of the the same gauges as the original.  The tensions will not change going from the original wire to XM Paulello as long as the gauge is the same, but the breaking percentages certainly do and that's the whole point of the exercise.  Stronger wire of the same gauge will have a lower breaking percentage, which means there is less stress in the wire.  To my ear (having made these substitutions a number of times) the tone sounds a bit more relaxed as a positive.

The area of greatest stress is at the coil.  There is the greatest bend there building up torsional forces and the string twists on its own axis down and in. the torsional forces from the twist are significant, so great that in this area the wire is already beginning plastic deformation almost from the moment the wire piano is first pulled to pitch.

I would take a different tack with the profile of the V bar.  Carefully reshape it, making sure the string imprints are completely gone.  Then poiish the surface with grits up to about 12,000 grit, and finish with Tungsten Disulfide Nano-powder rubbed in under pressure.  This will dramatically lower coefficient of friction of the surface.  When the string oscillates, it undergoes stick/slip which abrades the cast iron surface, which ultimately leads to breakage.

Hi Wim,

I did this on a Kawai RX2, and only replaced individual tuning pins that I deemed with my torque wrench to be on the loose side.  Big mistake.  I ended up with a dog's breakfast of tuning pin tightness.

Sometimes when I restring, particularly in the university setting, I am trying to leave options open for those who will come after me, so I upsize as little as possible.  Sometimes I retain the original pins if I can get away with it.  Sometimes that gives me a reasonable result, occasionally not.  If the pins need to removed rather than just threaded back a turn, (specifically, if I'm pulling the plate), I definitely upsize.

Any time I'm just threading the pin back a bit, I'm winding the coil for the new string on a dummy pin then transferring it to the pin in the block.

Floyd

I was asking about the tuning pins, not the bridge pins. 

If I can exactly match the size of the original bridge pins, I will not go for enlargement.  I will rely on the CA.  Nevertheless I will drill to deepen the holes as necessary so that I can avoid filing the tops of the new pins.  I typically use pins with rounded tops.  Maybe you're happy to file, and to eliminate the drilling step.  I forget exactly how far undersize I drill, but I think the appropriate bit sizes are specified in the Schaff and/or Pianotek catalogues.

The more often you can visit the piano, the more quickly it will stabilize.  I wish I could be more specific than that.  Of course at the outset you'll need to nudge the wires at all of the bends to speed up the process.

Floyd.. Thanks for the advice. When you've done this, did you go up one size on the pins, or used to originals?  How long before the piano was "stable"? 

Hi Wim,

It is my understanding that metal fatigue sets in at the terminations of the vibrating length, especially if the piano is played hard over an extended period of time.

If I were in your position, I would do (and have done) the following.  I would restring the treble with Paulello music wire, using the hybrid scaling strategy.  In practical terms, that means most of the treble would be strung with the high-tensile-strength XM wire.  This would give greater durability than the original stringing.  Wire diameters do not need to change from the original.  While I was at it, I would definitely dress the capo bar.  While the strings were off, I would also apply water-thin CA at the base of the bridge pins for give some insurance against future false beating.  (If I wanted to do even more, I might replace the pins, pre-soaking the new pins in McLube, then applying CA after installation.  This would give happier prospects for pin removal in regard to future repinning efforts. In such a case, the pins closest to the struts would not be replaced, due to the plate strut blocking their exit path.)  I have found the application of CA to the bridge pins to be somewhat risky with the strings in place, but almost foolproof with the strings off.

For what it's worth, I always go and re-read David Love's "Reshaping the Capo Bar in situ" (Pianotech 07-22-14) before I tackle the task.

I think this would do more than remediate the nuisance of string breakage.  I expect this would give an audible improvement to the sound in the treble.

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida. 

Dear Friends

I've got a 19 year old Yamaha C7 in a Jazz rehearsal room that gets played hard about 20 hours a week. For the past 4 years, strings in the 6th and 7th octave have been breaking. When it first happened I shaped the hammers, and then 2 years ago I replaced the hammers. But the strings are still breaking. The jazz piano professor asked me why the strings continue to break. I told her, after observing the player, that they are playing too hard. I also told her to put a monitor behind the player so that they can hear themselves, and not try to compete with the full band.  The room is carpeted, but it's still very loud in there. 

I heard that Yamaha's are known for breaking stings after about 20 years, especially in the upper register. Is there any truth to that? Would it make sense to restring the upper register? If so, should I also dress the capo bar? 

Other than telling the professor to teach the students to play softer, (she plays hard, too) is there any other advice you can give me to keep the strings from breaking.

Thanks

Wim Blees, RPT

University of North Florida.