Pianotech

  • 1.  Split Bridge Cap

    Registered Piano Technician
    Posted 12-29-2020 08:47
      |   view attached
    Hello All,

    I looking for suggestions how to repair this bridge cap.
    This is a Schimmel Upright 40 years old. other wise in great shape.
    Thanks

    Joe Morocco Needham MA

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    Joseph Morocco
    Needham MA
    781-449-9425
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  • 2.  RE: Split Bridge Cap

    Posted 12-29-2020 08:58
    Hey Joe,

    You might try tripping it on its back, pull the pin, and fill the hole with West System 105 epoxy resin and hardener. Wait a day or two for cure and re-drill. Straight epoxy/hardener, no fillers. You may have to wait an hour or two after applying, and add some more as it soaks in.   You'll need a hypo needle to fill the entire hole from the bottom up, without voids.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 3.  RE: Split Bridge Cap

    Posted 12-29-2020 09:26
    That is going to be an iffy repair.
    First do what Jim Ialeggio suggests. Use a wedge between the strut and the end of the bridge to clamp the split after injecting epoxy, not too tight.
    When the repair is complete, add a PitchLock coupler on the two right strings to pass some of the stress to the middle string and pin.

    http://pitchlock.com/pitch-lock-string-couplers/

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 4.  RE: Split Bridge Cap

    Registered Piano Technician
    Posted 12-29-2020 09:34
    Hi Joe  .......  I'd like to add to what Jim suggested  .......  destring the affected pin and if the small broken piece is still attached, wedge it in place by pressing an appropriately sized piece betwixt the broken part and the strut  .......  if you can.  Remove the wedge before applying the glue.  This will allow glue to get on the broken part better.  Remove the existing pin and fill the hole with Epoxy.  West System is a good choice.  Don't use the 5 minute stuff.  You'll need some strength to overcome the original failure  .....  which is now compromised.  Insert the pin and wedge before the glue hardens.  Clean up any oozage especially the bearing point  ...  that small contact where the string touches the bridge and the pin.  You could fashion a Popsicle (craft stick) stick to use as a small scraper.  Let the glue fully cure before putting side pressure back on it.  Take your time, think it through. 

    Basic rule of thumb ... that I'm aware of  ....  the longer the Epoxy takes to cure, the stronger it is.

    That's a really nice piano.  I hope this repair keeps it that way.

    Lar

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    Larry Fisher
    Owner, Chief Grunt, Head Hosehead
    Vancouver WA
    503-310-6965
    Working the gravy zone for the rest of my days.
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  • 5.  RE: Split Bridge Cap

    Posted 12-29-2020 20:11
    A pin block plug will fix it once and for all. I've also used a hammer shank on a smaller crack.

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    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
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  • 6.  RE: Split Bridge Cap

    Posted 12-29-2020 20:16
    Another bridge repair.

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    Regards,

    Jon Page
    mailto:jonpage@comcast.net
    http://www.pianocapecod.com
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  • 7.  RE: Split Bridge Cap

    Posted 12-29-2020 21:01
    the damn notch underneath the strut is going to really challenge this...why in heaven's name do manufacturers design these notches into the bridge/strut system?...nothing but trouble in the long term and lousy terminations in the short term.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 8.  RE: Split Bridge Cap
    Best Answer

    Posted 12-29-2020 21:16
    So here's a maybe.
    Move the unison over about 3mm to the left.
    Drill holes and add front and back pins for one string, then move all three strings over.
    String three goes through the pins for string two, string two goes through the pins for string one and string one gets new pins in the space to the left of the original pins.
    There's probably enough string length to the strike point and upper termination to result in just a small misalignment.

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    Ed Sutton
    ed440@me.com
    (980) 254-7413
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  • 9.  RE: Split Bridge Cap

    Registered Piano Technician
    Posted 12-29-2020 22:08
    I have repaired several bridges much like Jon describes. The really tricky part is drilling the hole for the plug straight with a foerstner bit. On a couple of these the bridge pins were short and I repaired with 1" which helps to increase the strength. You can also drill the pin with less side tilt to allow for more strength, and as Ed suggest alter string spacing a little if that helps. I do use gel CA just at the bottom of the hole to glue the plug in and follow with thin CA and accelerator to fully fill and cure the joint so you may drill for the new pins in 15 minutes or so.


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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 10.  RE: Split Bridge Cap

    Posted 12-29-2020 23:23
    Also important is to learn how to properly sharpen a chisel to a razor edge. Then cleaning up and notching will look professional. I use a Lie Neilsen chisel honing guide, lapping plate, waterstones ( 1,000-4,000-8,000) then buffing compound to a mirror finish.  A skill worth acquiring for any wood worker.
    -chris

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    Chernobieff Piano Restorations
    "Where Tone is Key"
    chernobieffpiano.com
    grandpianoman@protonmail.com
    Lenoir City, TN
    865-986-7720
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