Pianotech

  • 1.  Cleaning up WNG shanks

    Registered Piano Technician
    Posted 05-25-2021 09:28
    To all:

    For the second time in 45 years, I am replacing a new set of hammers because of bad felt.  the problem is that the top layers of felt are extremely soft, while the inner layers are  of normal density for this hammer maker.  I won't name the maker, as he is very good and reliable, and has replaced the bad set free of charge.  And I believe that the issue lies with his felt supplier rather than his handling in the making of the set.  

    None of the usual heroic measures were able to bring this set to an acceptable level.  No amount of doping. needling, and/or filing got them close.  I knew all that pretty early on but still had to go through the motions.

    Since the set has no further use, I split the tails in one or two places, and the cracking traveled up to and past the glue joint of the shank to the molding.  This has allowed me to remove the shank from the molding with relative ease using a hammer extractor..

    Most separated pretty cleanly, with little RX Gel residue left on the shank.  I want to clean up the rest, doing minimal damage to the shank interface, whether by chemical or mechanical means.

    Does anyone have any suggestions as the best means of cleaning the shanks in a minimally invasive manner?

    Thanks in advance to anything you have to offer.

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    William Truitt
    Bridgewater NH
    603-744-2277
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  • 2.  RE: Cleaning up WNG shanks

    Registered Piano Technician
    Posted 05-25-2021 09:56
    Will,

    I use straight acetone to dissolve CA. Can't imagine it could harm the shanks. 

    Pwg

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    Peter Grey
    Stratham NH
    pianodoctor57@gmail.com
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  • 3.  RE: Cleaning up WNG shanks

    Posted 05-25-2021 11:03
    Not sure on the solvent, but I took a piece of  3/32" steel scrap, drilled a hole using a no.11 bit (same as I use for boring the hammers), then cut the steel so there was only half of the bored hole left(bisected the hole). I use this to scrape residue off the shank, instead of using a straight razor or something like that, which will damage the carbon fiber.

    Do tell what solvent ends up working.

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    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
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  • 4.  RE: Cleaning up WNG shanks

    Registered Piano Technician
    Posted 05-26-2021 07:58
    Thanks Peter and Jim.  What I ended up doing was playing with the acetone on a rag and working to rub off the residue, thicker in some places than others.  That seemed like it was going to take next to forever.  I ended up using 3M  220 wet or dry sandpaper to carefully sand down the high spots of CA glue and also thin the shanks ever so slightly, as they were too tight in the bored hammers.  I did not sand into the carbon fiber, and there is plenty of epoxy surface on top of the fiber.  So I don't think I compromised the integrity of the shank, and I was able to control the process sufficiently.  

    I then cleaned the shank with acetone on a rag.

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    William Truitt
    Bridgewater NH
    603-744-2277
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