Pianotech

  • 1.  Fiberboard source?

    Registered Piano Technician
    Posted 04-21-2026 17:09
      |   view attached

    Does anybody have a source for the fiberboard type material as is found in the under string area covered in felt right behind the midsection agraffes on a Steinway? See photo.

     Thanks!



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    Tim Foster RPT
    New Oxford PA
    (470) 231-6074
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  • 2.  RE: Fiberboard source?

    Posted 04-21-2026 17:18

    On Steinways I carve mine out of hardwood on a 4' sander. Not hard to do either. The reason i do that is to have a higher profile so the sting will run parallel to the plate, rather than an incline.

    On other pianos i tend to use a brass half rod set up.

    -chris



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    Chernobieff Piano Restorations
    chrisppff@gmail.com
    Youtube@chernobieffpiano
    865-986-7720 (text only please)
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  • 3.  RE: Fiberboard source?

    Member
    Posted 04-22-2026 01:05
    Steinway sells them in huge sheets (24”x40”). It’s pretty expensive, but I got one a few years ago and I think it’s going to last me the rest of my life. It’s good key block shim material for New York Steinways that don’t have the new Hamburg style key blocks.

    Best,

    Luke


    Sent from my iPad




  • 4.  RE: Fiberboard source?

    Registered Piano Technician
    Posted 04-22-2026 02:16

    Fish paper

    https://www.mcmaster.com/products/fishpaper/



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    Steven Rosenthal RPT
    Honolulu HI
    (808) 521-7129
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    Original Message


  • 5.  RE: Fiberboard source?

    Registered Piano Technician
    Posted 04-23-2026 01:48

    Steven,

    You might be missing something valuable.

    I have long used fish paper for repairing broken or split keys (especially spinets).  Fish paper is a very tough and tear-resistant material that makes great reinforcement material for fragile key breaks.  Some brands or formulas don't take glue well, but if it does it is an excellent reinforcement for thin balance rail breaks.



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    Blaine Hebert RPT
    Duarte CA
    (626) 390-0512
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    Original Message


  • 6.  RE: Fiberboard source?

    Registered Piano Technician
    Posted 04-22-2026 08:01
    You can cut it from accordian folders from the office supply stores.

    Norman Cantrell 





  • 7.  RE: Fiberboard source?

    Registered Piano Technician
    Posted 04-22-2026 12:41

    I found this site a while back, I haven't ordered from there, but I think the "Vulcanized Fiber" is the same thing.  

    https://www.barplate.com/product-category/makeready-supplies/counterboard/



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    Tom Dowell
    Hulbert Piano
    tom@hulbertpiano.com
    262-221-0792
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  • 8.  RE: Fiberboard source?

    Registered Piano Technician
    Posted 04-22-2026 13:44

    I have used acetal copolymer with happy results. Can be shaped like hardwood. 



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    Floyd Gadd RPT
    Regina SK
    (306) 502-9103
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    Original Message