[CAUT] Re: swelling knuckles -- old thread

[Otto Keyes]

Some time back I mentioned encountering a problem with bobbling hammers on a
D after I had hit them with a shot of dry spray teflon, but then forgot to
report the results.

>From some of your suggestions I was afraid I was going to have to re-pin
everything (fairly new parts), but the pinning turned out to be just fine.
Though I don't know how much they changed, since I didn't measure just
before the treatment, the let-off was consistently closer, so the knuckles
had swelled just slightly.  This, coupled with the fact that the regulating
button felt on the jack had compressed slightly, allowing it to sit just a
bit deep under the knuckle, caused the hammers to double-strike.  Once those
2 elements were dealt with, it settled down to work like a real piano again.
My guess is that something in the aerosol carrier in the teflon spray caused
the knuckles to swell just enough to cause problems when put together with
other minor deficeincies.  I doubt that it would have caused a problem had I
just sprayed it on the balancier & top of the jack.

Otto