Pianotech

My adventure in piano repair today involved replacing the rubber grommets on a Wurlitzer spinet piano.  This grommet fits into a metal spade driven into the end of the key.  I am trying to figure out why some (maybe 10%) of those metal spades were very rusted while the rest were not (ie: zero, zilch absolutely no rust at all).  There didn't seem to be any pattern to it (like what a spilled drink might cause).  Any thoughts on why this might have happened and how I can prevent it from happening again would be greatly appreciated.

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Neil Vanderschaaf
Round Rock TX
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Or it could be bad plating. 

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Steven Rosenthal RPT
Honolulu HI
(808) 521-7129
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Original Message:
Sent: 02-18-2026 15:13
From: Wim Blees
Subject: Rust on the key end spades of a lift action (spinet) piano

Sounds like mice pee, or maybe cockroaches. 

There is nothing you can do to stop that, short of getting rind of the animals

Wim Blees, RPT

I believe this is where as piano technicians we need to learn some chemistry too. (i am not good at it at all though) May be bad plating or even bad material (metal) I had similar ones once. I had to use steel wool to clean the rusty ones and took some time. 

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Rays Koshy
Philadelphia PA
(267) 401-6705
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high humidity , possible reaction to crumbling rubber grommets , The part is a key end fork. Look for rust on other metal parts including tuning pins, coils , screws , bracket 

Not sure what your humidity is like there but the piano may have been in many places before you saw it. You could try using a Rustoleum product on all of them to treat the rust and prevent it . There used to be a bluing solution that could be put on tuning pins and coils it was very effective . Schaff supply carried it and I think it can still be purchased from some metal supply companies

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James Kelly
Owner- Fur Elise Piano Service
Pawleys Island SC
(843) 325-4357
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Rodent urine is quite corrosive and is usually deposited randomly as a territorial marker, so I would guess that this is rodent urine.  The disease risk is slight (unless there is an active infestation) but if you are over-cautious a light spray with Lysol or any other disinfectant is safe.

The day the last spinet goes to the dump will be a day of celebration for us all!

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Blaine Hebert RPT
Duarte CA
(626) 390-0512
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