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Crummy plate finish

  • 1.  Crummy plate finish

    Posted 07-02-2018 18:48
    I just brought in a Yamaha C3 (about 1973) for a new block and strings, etc. It had been restrung about 25 years ago (stringer evidently didn't realize that the bridge gauges were metric and strung everything one half size too big).

    Anyway, whoever did it also sprayed the plate with "something" that was thick, not very durable, poor adhesion, now cracking and flaking. Looks pretty lousy.

    Problem is, if I try to spray over this (which would now become the substrate), it is obviously going to do exactly what the substrate is now doing. Ain't going to work too well.

    Any suggestions as to how I might get that off (back down to the original plate finish that actually doesn't look half bad, from what I can see) WITHOUT totally stripping the thing would be appreciated.

    Is bead blasting an option? Never done it outside a cabinet.

    I did not realize how weak this coating was when I estimated it.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
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  • 2.  RE: Crummy plate finish

    Posted 07-02-2018 20:33
    Sanding is a safe bet.

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    Regards,

    Jon Page
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  • 3.  RE: Crummy plate finish

    Posted 07-02-2018 22:37
    On some plates like this I have found windex and 4/O steel wool kept wet works to remove poorly adhered paint without making any bad scratches. I keep a spray bottle by my side to rinse off the old paint as it loosens. After it dries, I still sand with 220 lightly to start the surface preparation and switch to 320 pretty quick. Then fill scratches with appropriate fillers and sand those areas again. Spray one coat of gold and sand that with 320 when it dries. Re-coat sanded areas as needed. Then wet sand with 1500 grit very lightly. Dry plate. Install buffed agraffes  and spray as thin as possible a clear coat over everything. Let dry overnight and wax with car wax before installing plate in piano. Wax soundboard finish also, then dust will have a more difficult time sticking. Got this idea from Joe Garrett.

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    Edward McMorrow
    Edmonds WA
    425-299-3431
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  • 4.  RE: Crummy plate finish

    Posted 07-03-2018 12:48
    Thanks Jon and Ed. I will attempt part or all of this.

    Pwg

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    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------