Pianotech

  • 1.  Bridge stain removal

    Registered Piano Technician
    Posted 05-14-2023 15:54
      |   view attached

    I'm looking to remove these drink stains from a Bechstein B bridge.  I plan to replace bridge pins, strings and bearing felt.  I'm asking for any advice on  removal.  It is likely soda our wine, and has been there for at least 10 years.  The cap is unfinished as afar as I'm able to ascertain. My thought is to first try denatured alcohol, but am wondering what other options others have tried.  Will it require bleaching with oxalic acid perhaps?  And will that affect the wood structure negatively if used?

    Thanks,



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    Joe Wiencek

    New York NY
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  • 2.  RE: Bridge stain removal

    Registered Piano Technician
    Posted 05-14-2023 16:01
    If the stain is only on the surface of the bridge, you can probably clean it with Simply Green and then sand it. (after removing the pins).  But if the stain has penetrated the wood, it might require a more aggressive method. But you don't want to sand the wood. 
     





  • 3.  RE: Bridge stain removal

    Registered Piano Technician
    Posted 05-14-2023 18:05

    If you get the wood wet with any water-based cleaner, it will swell the surface a little. Finishers often do this with water, let it dry, and then sand it smooth again. That makes the surface less apt to raise the grain when doing the final finishing coats. If you use something like alcohol, it might have the same effect as water because it has water in it. It might make the stain soak into the wood more than it already has. I doubt that the stain will ever be totally removed.
    I don't know if raising the grain is going to affect the bridge function when it dries. Adding a finish over the area might affect it as well. Or maybe not. I do know that once I tried using epoxy putty on a bridge, or some kind of plastic, and the tone died. You want the wood in contact with the string to be firm and not rubbery.
    Alternatively, you "could" route out the section of the bridge and add a new cap. Or use some touchup color to paint over the dark areas.
    I got a lot of information by Googling "Removing Wine Stains from Wood".
    Many possibilities.. 



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    Paul McCloud, RPT
    Accutone Piano Service
    www.AccutonePianoService.com
    pavadasa@gmail.com
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  • 4.  RE: Bridge stain removal

    Registered Piano Technician
    Posted 05-15-2023 18:30

    I've often wondered if there is a reasonable explanation for manufacturers' universal neglect of finishing the two most vulnerable parts of the bellywork of a grand: the bridges and the damper wire guide rail.  Is there some perceived danger of warping?  I don't see it.  Since we technicians see the result of similar spillage on an almost daily basis, from our point of view the calculus of risk and reward is definitely skewed in the direction of finishing these parts which I will always do if I have the piano in the shop for restringing.  We can make them functionally "good as new" but it's often difficult to make them look that way

    For general clean up I keep a spray bottle of water with a dollop of  dish detergent and ammonia. The sheer volume of different remedies available for cleaning up crud is a testimony either to the hopelessness of the endeavor (the crud always wins in the end) or the gullibility of the general public.



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    Cecil Snyder RPT
    Torrance CA
    (310) 542-7108
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