CAUT

  • 1.  Loose damper guide bushings

    Registered Piano Technician
    Posted 02-21-2022 16:18
    Greetings all,
    Recently I posted about the possibility of having to replace one damper guide bushing in a 1937 Steinway L.
    This was theoretical, based on the what the customer told me. However, when I finally got to the piano, here's what I actually found:

    All the damper guide rail bushings are too loose. I found it odd that they would be so loose since the piano was apparently "rebuilt" about 20 years ago. Maybe the rebuilder neglected to rebush the rail? I could understand that kind of wear in an institutional piano, but not in a home customer.

    My question is what effect VS Profelt will have. I have some, but have never used it for this. I've seen the recommended method: remove the dampers, treat, and size with #7 bridge pins. The question is, what are the chances I can do this without damper removal? Can I treat with dampers in place an ease with an umbrella tool if necessary?
    If they are very loose, is there a possibility they won't even need easing?

    I'm planning to stop by and try it on just one bushing, like A0, and see what happens. Of course, it would be nice not to have to remove all the dampers and make two trips...​

    thanks

    ------------------------------
    Scott Cole, RPT
    rvpianotuner.com
    Talent, OR
    (541-601-9033
    ------------------------------


  • 2.  RE: Loose damper guide bushings

    Registered Piano Technician
    Posted 02-21-2022 23:54
    Scott,
    On a Steinway grand of that vintage, I would suspect that the originals were double bushed, and the rebuilder replaced with single (something I have seen often). If the current ones are single, that is almost certainly the case, and those single bushings won't swell enough to take up the gap.

    In that scenario, one option might be to use the current Steinway method of leaning the wire against one side of the bushing. This takes some refined wire bending (mostly the bottom-most bend, with a bit of compensation to the top bend to have the damper rise vertically) to get just enough lean to make the wire steady, but not so much that there is drag. However, that may shift the some or all of the damper heads enough that the felt may not line up well with the strings, meaning you would need to adjust the top two bends as well.

    The other option is to come up with a pair of two thicknesses of bushing cloth to match the originals, to take up enough gap to leave just the right size hole in the middle. This is troublesome, but it is harder to come up with a single thickness that will do the job. In any case, it would most efficiently mean removing dampers and taking the rail to the shop.