Pianotech

Several month ago I reported on how by tightening a few rim screws on a 5 year old grand piano, it solved a stability problem. A brief history, for the past 5 years another tuner just couldn't keep the middle 2 octaves in tune, especially d4 - c5. When I was asked to tune the piano, I had a hell of a time getting that part of the piano in tune, and stay in tune even as I was working on it. I wound up taking the piano in trade for one of my rebuilt Steinways, so one of the first things I did when I got the piano, was tighten the rim screws. There were about 4 screws in the bend of the rim that all turned about a quarter turn. I tuned the piano and noticed right away that it responded much better.

Fast forward 6 months, and I just tuned the piano in the customer's home. She lives in a very exclusive area of Hawaii, down 50 steps next to the ocean. After 6 months, and that move, the piano was on pitch and just barely out of tune.

What's interesting is that after I posted my findings 6 months ago, several prominent technicians, including our recently departed friend, Ron, argued that just tightening rim screws shouldn't make a difference in tuning stability. That was the only thing I did different to the piano. If it wasn't the tightening of the rim screws that made the difference, I want to ask what else could it be? But I'm sticking to my story.



------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Seeking clarification, and some questions:
Was the 'trade' temporary?  Did you lend a piano of yours while you took her piano in to work on?
Is there a reason why you wouldn't have inspected (and tightened) plate bolts/screws at the time(s) you were tuning?

My next question(s) would have invoked Ron's usual ire, in that they don't provide any useful first-hand knowledge, but I will continue to occasionally tempt the fates, with the same trepidation with which I would have, were he still among us:
- Could the mass and design of plates make a difference with regard to the effect of their being either firmly or erratically mated to rim?
- What movement is being permitted by a plate that has one or more screws that might be 1/4 of a turn loose?  

Having gone this far, I'm recalling that Del has recently published a series of articles about plates.  I can't stop to look right now, but, if no one posts this information before, I'll follow up when I can.

My reason for always checking plate bolts is quite self serving, and stupid.  I feel like I have to justify carrying around the added weight of the assorted sockets, extension, 3/8" drive breaker bar handle.    Note -  I tried the universal spring-loaded socket.  While I liked the idea, it didn't work well, and would often get stuck. 

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Original Message:
Sent: 01-11-2017 23:12
From: Willem Blees
Subject: tight plate screws

Several month ago I reported on how by tightening a few rim screws on a 5 year old grand piano, it solved a stability problem. A brief history, for the past 5 years another tuner just couldn't keep the middle 2 octaves in tune, especially d4 - c5. When I was asked to tune the piano, I had a hell of a time getting that part of the piano in tune, and stay in tune even as I was working on it. I wound up taking the piano in trade for one of my rebuilt Steinways, so one of the first things I did when I got the piano, was tighten the rim screws. There were about 4 screws in the bend of the rim that all turned about a quarter turn. I tuned the piano and noticed right away that it responded much better.

Fast forward 6 months, and I just tuned the piano in the customer's home. She lives in a very exclusive area of Hawaii, down 50 steps next to the ocean. After 6 months, and that move, the piano was on pitch and just barely out of tune.

What's interesting is that after I posted my findings 6 months ago, several prominent technicians, including our recently departed friend, Ron, argued that just tightening rim screws shouldn't make a difference in tuning stability. That was the only thing I did different to the piano. If it wasn't the tightening of the rim screws that made the difference, I want to ask what else could it be? But I'm sticking to my story.



------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Hi David

answers interspersed.


Seeking clarification, and some questions: Was the 'trade' temporary?  No. She bought my Steinway. I took the K&C.

Did you lend a piano of yours while you took her piano in to work on? No, See above

Is there a reason why you wouldn't have inspected (and tightened) plate bolts/screws at the time(s) you were tuning? I was going to tighten the plate screws on my next appointment, but she bought my Steinway before I could do that.

My next question(s) would have invoked Ron's usual ire, in that they don't provide any useful first-hand knowledge, but I will continue to occasionally tempt the fates, with the same trepidation with which I would have, were he still among us: - Could the mass and design of plates make a difference with regard to the effect of their being either firmly or erratically mated to rim? - What movement is being permitted by a plate that has one or more screws that might be 1/4 of a turn loose?  Now you're getting into a real I am not qualified to answer. All I know about the effects of rim bolts on tuning is what I've read and heard. And what I've heard is that loose plate bolts will cause tuning instability. As far as to why those screws were loose, the only explanation is that they were not tightened down at the factory. That is why the previous tuner had difficulty keeping the piano in tune, but he never bothered to find out why. 

Having gone this far, I'm recalling that Del has recently published a series of articles about plates.  I can't stop to look right now, but, if no one posts this information before, I'll follow up when I can. My reason for always checking plate bolts is quite self serving, and stupid.  I feel like I have to justify carrying around the added weight of the assorted sockets, extension, 3/8" drive breaker bar handle.    Note -  I tried the universal spring-loaded socket.  While I liked the idea, it didn't work well, and would often get stuck. I never check plate screws. I've heard that some techs do this as part of routine maintenance, on both upright and grand pianos. But I've never done it.

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Original Message:
Sent: 01-13-2017 11:27
From: David Skolnik
Subject: tight plate screws

Seeking clarification, and some questions:
Was the 'trade' temporary?  Did you lend a piano of yours while you took her piano in to work on?
Is there a reason why you wouldn't have inspected (and tightened) plate bolts/screws at the time(s) you were tuning?

My next question(s) would have invoked Ron's usual ire, in that they don't provide any useful first-hand knowledge, but I will continue to occasionally tempt the fates, with the same trepidation with which I would have, were he still among us:
- Could the mass and design of plates make a difference with regard to the effect of their being either firmly or erratically mated to rim?
- What movement is being permitted by a plate that has one or more screws that might be 1/4 of a turn loose?  

Having gone this far, I'm recalling that Del has recently published a series of articles about plates.  I can't stop to look right now, but, if no one posts this information before, I'll follow up when I can.

My reason for always checking plate bolts is quite self serving, and stupid.  I feel like I have to justify carrying around the added weight of the assorted sockets, extension, 3/8" drive breaker bar handle.    Note -  I tried the universal spring-loaded socket.  While I liked the idea, it didn't work well, and would often get stuck. 

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Original Message:
Sent: 01-11-2017 23:12
From: Willem Blees
Subject: tight plate screws

Several month ago I reported on how by tightening a few rim screws on a 5 year old grand piano, it solved a stability problem. A brief history, for the past 5 years another tuner just couldn't keep the middle 2 octaves in tune, especially d4 - c5. When I was asked to tune the piano, I had a hell of a time getting that part of the piano in tune, and stay in tune even as I was working on it. I wound up taking the piano in trade for one of my rebuilt Steinways, so one of the first things I did when I got the piano, was tighten the rim screws. There were about 4 screws in the bend of the rim that all turned about a quarter turn. I tuned the piano and noticed right away that it responded much better.

Fast forward 6 months, and I just tuned the piano in the customer's home. She lives in a very exclusive area of Hawaii, down 50 steps next to the ocean. After 6 months, and that move, the piano was on pitch and just barely out of tune.

What's interesting is that after I posted my findings 6 months ago, several prominent technicians, including our recently departed friend, Ron, argued that just tightening rim screws shouldn't make a difference in tuning stability. That was the only thing I did different to the piano. If it wasn't the tightening of the rim screws that made the difference, I want to ask what else could it be? But I'm sticking to my story.



------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Original Message------

Seeking clarification, and some questions:
Was the 'trade' temporary?  Did you lend a piano of yours while you took her piano in to work on?
Is there a reason why you wouldn't have inspected (and tightened) plate bolts/screws at the time(s) you were tuning?

My next question(s) would have invoked Ron's usual ire, in that they don't provide any useful first-hand knowledge, but I will continue to occasionally tempt the fates, with the same trepidation with which I would have, were he still among us:
- Could the mass and design of plates make a difference with regard to the effect of their being either firmly or erratically mated to rim?
- What movement is being permitted by a plate that has one or more screws that might be 1/4 of a turn loose?  

Having gone this far, I'm recalling that Del has recently published a series of articles about plates.  I can't stop to look right now, but, if no one posts this information before, I'll follow up when I can.

My reason for always checking plate bolts is quite self serving, and stupid.  I feel like I have to justify carrying around the added weight of the assorted sockets, extension, 3/8" drive breaker bar handle.    Note -  I tried the universal spring-loaded socket.  While I liked the idea, it didn't work well, and would often get stuck. 

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

No Michael, you didn't miss it.  Torque specs haven't been discussed, though, it might have come up eventually.  Continuing to respond, based on my thorough lack of real information, I would surmise that the role of torque specs in automobiles is rather different than the concerns regarding piano plate bolts. In the former, I would guess that the main issue  would be any tendency to loosen with continued vibration.  Not likely with pianos.  Does the plate thickness change?  Not likely.  The soundboard dowels and rim?  probably.  If that's the case, does that alter the flexure status of the plate?  If I snug the bolts in August, and I'm able to snug again in January, am I altering the position of the plate from where it was in August?   

Also, I suspect that torque measurement in machinery is intended to represent compressive force applied to a (more or less) running fit threading, whereas the plate bolts and screws, being in wood, will have a certain amount of friction of their own, apart from how much compression is being applied (not to mention crushing of plate dowels, if present).  

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Original Message:
Sent: 01-14-2017 04:44
From: Michael Gamble
Subject: tight plate screws

Interestingly, David, the subject here is 'tight plate screws' yet I see no mention of torque wrenches! (unless I just didn't see them mentioned) I have a splendid torque wrench which would really weigh your kit bag down . . . .  but how useful it is! - yet how infrequently used!  Has anyone mentioned the ideal torque applied to a plate-rim screw? In engineering circles, the automotive industry in particular, one cannot avoid it!

Michael   UK

There can't be a single ideal torque measurement for plate screws because of fluctuating relative humidity in many parts of the country (and the world).  If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-14-2017 04:44
From: Michael Gamble
Subject: tight plate screws

Interestingly, David, the subject here is 'tight plate screws' yet I see no mention of torque wrenches! (unless I just didn't see them mentioned) I have a splendid torque wrench which would really weigh your kit bag down . . . .  but how useful it is! - yet how infrequently used!  Has anyone mentioned the ideal torque applied to a plate-rim screw? In engineering circles, the automotive industry in particular, one cannot avoid it!

Michael   UK

Kent says:
 If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

What does "tightened hard" mean?  What does "too tight" mean?

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Original Message:
Sent: 01-15-2017 07:10
From: Kent Burnside
Subject: tight plate screws

There can't be a single ideal torque measurement for plate screws because of fluctuating relative humidity in many parts of the country (and the world).  If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-14-2017 04:44
From: Michael Gamble
Subject: tight plate screws

Interestingly, David, the subject here is 'tight plate screws' yet I see no mention of torque wrenches! (unless I just didn't see them mentioned) I have a splendid torque wrench which would really weigh your kit bag down . . . .  but how useful it is! - yet how infrequently used!  Has anyone mentioned the ideal torque applied to a plate-rim screw? In engineering circles, the automotive industry in particular, one cannot avoid it!

Michael   UK

I was responding to the suggestion that a specific torque number could be the universal standard for tightening plate screws.  My point is that even if such a setting were achieved in the dry months, the screws would be too tight six to eight months later, at least in areas where RH fluctuates widely.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-15-2017 07:25
From: David Skolnik
Subject: tight plate screws

Kent says:
 If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

What does "tightened hard" mean?  What does "too tight" mean?

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Original Message:
Sent: 01-15-2017 07:10
From: Kent Burnside
Subject: tight plate screws

There can't be a single ideal torque measurement for plate screws because of fluctuating relative humidity in many parts of the country (and the world).  If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-14-2017 04:44
From: Michael Gamble
Subject: tight plate screws

Interestingly, David, the subject here is 'tight plate screws' yet I see no mention of torque wrenches! (unless I just didn't see them mentioned) I have a splendid torque wrench which would really weigh your kit bag down . . . .  but how useful it is! - yet how infrequently used!  Has anyone mentioned the ideal torque applied to a plate-rim screw? In engineering circles, the automotive industry in particular, one cannot avoid it!

Michael   UK

I agree that specific torque specs are irrelevant.  I'm questioning what we mean by "too tight".  What do you think will happen in the example you provided?  What's the difference between tight enough and too tight? or not tight enough?

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Original Message:
Sent: 01-16-2017 07:03
From: Kent Burnside
Subject: tight plate screws

I was responding to the suggestion that a specific torque number could be the universal standard for tightening plate screws.  My point is that even if such a setting were achieved in the dry months, the screws would be too tight six to eight months later, at least in areas where RH fluctuates widely.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-15-2017 07:25
From: David Skolnik
Subject: tight plate screws

Kent says:
 If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

What does "tightened hard" mean?  What does "too tight" mean?

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Original Message:
Sent: 01-15-2017 07:10
From: Kent Burnside
Subject: tight plate screws

There can't be a single ideal torque measurement for plate screws because of fluctuating relative humidity in many parts of the country (and the world).  If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-14-2017 04:44
From: Michael Gamble
Subject: tight plate screws

Interestingly, David, the subject here is 'tight plate screws' yet I see no mention of torque wrenches! (unless I just didn't see them mentioned) I have a splendid torque wrench which would really weigh your kit bag down . . . .  but how useful it is! - yet how infrequently used!  Has anyone mentioned the ideal torque applied to a plate-rim screw? In engineering circles, the automotive industry in particular, one cannot avoid it!

Michael   UK

David, When I went to the Little Red Schoolhouse, I asked LaRoy Edwards
this very question. His reply to "How tight is tight?" was "Snug."
the same about action screws in the prepping of new pianos. So what is
the right answer? Clark
--
Clark A. Sprague, RPT www.clarkspianoservice.com


Original Message------

Kent says:
 If the screws are tightened hard in the winter when RH is low, they will be too tight when spring and summer come.

What does "tightened hard" mean?  What does "too tight" mean?

------------------------------
David Skolnik
Hastings-on-Hudson NY
914-231-7565
------------------------------

Thanks for sharing this, Clark.  "Snug" is my aim when RH is normal or high; in the dry season (below 35 or so) I settle for "not loose."  Del Fandrich contributed an excellent article on this topic to PTJ about a year ago, in which he points out that some pianos should not have their plate screws/bolts changed, Baldwins with the Accu-just hitch pins being only the most obvious example.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-16-2017 20:25
From: Clark Sprague
Subject: tight plate screws

David, When I went to the Little Red Schoolhouse, I asked LaRoy Edwards
this very question. His reply to "How tight is tight?" was "Snug."
the same about action screws in the prepping of new pianos. So what is
the right answer? Clark
--
Clark A. Sprague, RPT www.clarkspianoservice.com

Agree with Kent.

------------------------------
John Formsma, RPT
New Albany MS
------------------------------

Original Message:
Sent: 01-17-2017 07:37
From: Kent Burnside
Subject: tight plate screws

Thanks for sharing this, Clark.  "Snug" is my aim when RH is normal or high; in the dry season (below 35 or so) I settle for "not loose."  Del Fandrich contributed an excellent article on this topic to PTJ about a year ago, in which he points out that some pianos should not have their plate screws/bolts changed, Baldwins with the Accu-just hitch pins being only the most obvious example.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-16-2017 20:25
From: Clark Sprague
Subject: tight plate screws

David, When I went to the Little Red Schoolhouse, I asked LaRoy Edwards
this very question. His reply to "How tight is tight?" was "Snug."
the same about action screws in the prepping of new pianos. So what is
the right answer? Clark
--
Clark A. Sprague, RPT www.clarkspianoservice.com

Since the purpose of a screw (primarily a wood screw) is to keep something secure and free from movement (but without breaking stuff), but at the same time allow for adjustment further on down the road (due to changes in the dimensions of the secured part or parts therein) it makes sense that plate screws should be tight (snug plus a tad more) and checked every now and then. How often? Maybe every 5-10 years?  If the piano is in a totally uncontrolled environment that fluctuates between extremes, it would be common sense to check them more often, especially in the dry time.

Obviously, over-tightening of anything carries the risk of damage. Since in the factories these days plate bolts are usually put in with air-driven impact tools, it is conceivable that a few here and there are likely to get overdone since it can sometimes be hard to judge when the time to stop has come, leading to premature failure in the field. We should resist the urge to really crank down on these things since we could end up doing the same thing.

I can fully understand why loose plate screws (1/4 turn on a very coarse thread is loose in my book) could contribute to tuning instability, since we are dealing with 20 or so tons of tension. It doesn't take much movement (in a critical spot) to make things hard to control.  In fact, it only takes less than .002" of case expansion to lose 1/16" of soundboard crown.  (Do the math!)

Also occasionally, a buzz will develop when a plate screw(s) is not fully tight. This can be a bear to track down but it happens. This is another reason to check them every now and then and adjust according to common sense.  We shouldn't need a torque wrench...we are the torque wrench.

Pwg

------------------------------
Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com
------------------------------

Original Message:
Sent: 01-17-2017 10:22
From: John Formsma
Subject: tight plate screws

Agree with Kent.

------------------------------
John Formsma, RPT
New Albany MS
------------------------------

Original Message:
Sent: 01-17-2017 07:37
From: Kent Burnside
Subject: tight plate screws

Thanks for sharing this, Clark.  "Snug" is my aim when RH is normal or high; in the dry season (below 35 or so) I settle for "not loose."  Del Fandrich contributed an excellent article on this topic to PTJ about a year ago, in which he points out that some pianos should not have their plate screws/bolts changed, Baldwins with the Accu-just hitch pins being only the most obvious example.

------------------------------
Kent Burnside, RPT
Franklin TN
615.430.0653
------------------------------

Original Message:
Sent: 01-16-2017 20:25
From: Clark Sprague
Subject: tight plate screws

David, When I went to the Little Red Schoolhouse, I asked LaRoy Edwards
this very question. His reply to "How tight is tight?" was "Snug."
the same about action screws in the prepping of new pianos. So what is
the right answer? Clark
--
Clark A. Sprague, RPT www.clarkspianoservice.com