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Hammer repair - a screwy alternative

  • 1.  Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 28 days ago
    I recently tuned an ancient Wurlitzer spinet that had three hammers with separating hammer felt. I repaired them in-piano using contact cement which worked well but was not as snug as I would have liked. Initially, I tried CA glue but was not happy with the result. Attached is an alternative method I devised at home using an intentionally separated hammer. With the right tools, it is pretty quick, super tight and looks like it can be done in the piano. In addition, you don't end up with sticky fingers. Perhaps this has been done before,  I used #4 x 3/4 sheet metal screw and a 7/64 drill bit.
    Repaired hammer


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    Randy Prentice
    Tucson AZ
    520-749-3788
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  • 2.  RE: Hammer repair - a screwy alternative

    Posted 28 days ago
    Why not?
    I think it looks clean and good.
    Thanks Randy for sharing.
    Peter

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    Petrus Janssen
    Peachtree City GA
    678-416-8055
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  • 3.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 28 days ago
    Can't do in the piano if it's the bottom separating.

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    Larry Messerly, RPT
    Bringing Harmony to Homes
    www.lacrossepianotuning.com
    ljmesserly@gmail.com
    928-899-7292
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  • 4.  RE: Hammer repair - a screwy alternative

    Posted 28 days ago
    What was it about the result of using CA glue that made you sad?

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
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  • 5.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 28 days ago
    Yep. You are correct, Larry.

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    Randy Prentice
    Tucson AZ
    520-749-3788
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  • 6.  RE: Hammer repair - a screwy alternative

    Posted 27 days ago
    How about a quick clamp? A new invention.
    Drill a hole and thread a piece of piano wire through a rectangular piece of metal that fits the hammer. Tie a knot in the wire.  Drill the hole all the way through the hammer and feed the wire with the washer through from the bottom. Slide another washer over the top and make a cam lever to grab and tighten the wire. Remove when the glue sets and you probably won't see the hole.





  • 7.  RE: Hammer repair - a screwy alternative

    Member
    Posted 28 days ago
    Small drywall screws would work possibly without drilling . You would need to take the action out to get to the loose felt on the other side of the hammer. CA glue could seep into the felt and harden it. I have seen some good repairs done using strong twine

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    James Kelly
    Owner- Fur Elise Piano Service
    Pawleys Island SC
    843-325-4357
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  • 8.  RE: Hammer repair - a screwy alternative

    Posted 28 days ago
    Just use thick CA and you won't have any problems with the glue soaking into the felt.

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
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  • 9.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 27 days ago
    James Kelly - Your drywall screw idea is very interesting. Here's a thought: Say you have a hammer that is solid on the top half but pulled away on the bottom half. I wonder if a longer fine thread drywall screw going through the top could pierce through the molding and "bite" into the bottom felt well enough to pull it back into place. Maybe apply some glue as well. Possibly do a partial drilling on the top half...far enough to get through molding which would eliminate any undo pressure on the top half as well as the possibility of splitting the molding. An in-piano solution?

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    Randy Prentice
    Tucson AZ
    520-749-3788
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  • 10.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 28 days ago
    Hi, Terry. Yes, I used the gel variety CA  glue but must not have applied enough or for long enough. The felt just pulled away after releasing pressure.

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    Randy Prentice
    Tucson AZ
    520-749-3788
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  • 11.  RE: Hammer repair - a screwy alternative

    Posted 27 days ago
    Randy - Not sure why the felt would pull away after releasing pressure. I've done this many times with thick CA with great success. Because if one side of the felt has come loose, I figure the other side isn't far behind, so I remove the felt completely from the molding. Then I make sure to apply kicker to the wooden molding on both sides. On an upright I will use some sort of applicator (Q-tip, piece of wood, business card, etc.) to get kicker on the bottom side of the molding. Apply a nice line of thick CA all along where it meets the molding to the felt and then clamp in place with my fingers for maybe ten seconds or so and it always sticks for me.

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
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  • 12.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 27 days ago
    Here’s a thought: Does anyone make hammer staples? Brooks? Ronsen? Renner? Use your favorite glue and clamping method, then drill a small hole where your staple would go. Install the staple. Done.

    I’ve never done that procedure, but it’s clearly part of hammer manufacutring history. It’s a matter of finding staples. Better than using twine, I think. And I wouldn’t want to leave a screw/washer in the hammer because of weight issues and cosmetics.

    Richard West




  • 13.  RE: Hammer repair - a screwy alternative

    Posted 27 days ago
    Randy - Rather than a drywall screw - and I still say thick CA is the answer - but if one were going with a mechanical fastener, then I should think a small diameter appropriate length aluminum rivet with a washer on the bottom side would do the trick. It would make it tight, draw the two felt tails together against the molding and be very lightweight - and could do in the piano on a vertical.

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    Terry Farrell
    Farrell Piano Service, Inc.
    Brandon, Florida
    terry@farrellpiano.com
    813-684-3505
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  • 14.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 27 days ago
    Hey Richard, thanks for your input. I'll research your suggestion regarding staples. Maybe there is actually a device out there that will insert hammer staples on-the-fly. Interestingly, the Steinway and Yamaha hammer samples I have, sport staples that inserted deep and are almost impossible to remove. Where as, the 20 year old Kawai hammers I worked on a while back used more basic U shaped staples which pop out quite easily. Regarding your comment about extra hammer weight - I think generally, that pianos with faulty hammers are usually so old and crappy that the extra weight from a screw and a washer is probably a good thing.

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    Randy Prentice
    Tucson AZ
    520-749-3788
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  • 15.  RE: Hammer repair - a screwy alternative

    Posted 27 days ago
    hello Richard,
    i would not be concerned about cosmetics and weight issues with old pianos that are in that condition where the owner does not want to invest in replacing hammers. As long as it works and does not interfere with the working.
    I have actually made sort of staples by using the smallest gauge of piano wire, bent in a U-shape, drilling two small holes from top to bottom, inserting each leg of the u shaped wire through the separate holes and as they protrude from the bottom, grip them with vise grip pliers and twisting them several times, snipping them off and bend the twisted wires flush to the hammer felt.
    I also use the thick CA glue with this as well.
    Can't do it in the piano though.
    If those staples are available, it would be faster and nicer looking though.
    Peter

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    Petrus Janssen
    Peachtree City GA
    678-416-8055
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  • 16.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 27 days ago
    Of all the approaches I've seen, I think whoever thought of the zip-tie method is the best. Was that Jon Page...? Wouldn't be surprised. If not, whoever did is SMART. (Not that others are not...but).

    However Randy, your screw method can also be used simply for increasing mass where needed e.g. at bass/tenor break. Very good idea!

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 17.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 27 days ago
    Peter, the zip tie solution occurred to me as well, However, I had two reservations. .

    1. A pair of zip tied hammers adjacent to each other might result in clearance issues. I know the zip ties can be had in pretty tiny sizes so that might be a non-issue..

    2. The zip tie might want to creep down to the narrower portion of the hammer. But if they can be pulled tight enough to dig into the felt and possibly add a bead of CA glue, it could work.

    That's my spin. I agree it is the most elegant solution. Maybe someday I'll run across another piano with separated hammers.so I can try it.


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    Randy Prentice
    Tucson AZ
    520-749-3788
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  • 18.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 27 days ago
    It was John Rhodes. And he solved the 'creep down' issue with another zip tie, around the hammer to keep the clamping one in place.

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    Cindy Strehlow, RPT
    Urbana, IL
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  • 19.  RE: Hammer repair - a screwy alternative

    Registered Piano Technician
    Posted 27 days ago
    Thank you Cindy!

    Pwg

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