Sticking Jacks

[Philip Jamison]

   I'm working on an Acrosonic console from the '50s with a sticky
treble. Most notes in the top third stick after much play (maybe once in
30 hits). It's very erratic. I eased the keys and lubed the flanges
which only partially helped. The whippen stays up, not the key, but the
whippen drops when the hammer is pushed forward just a bit, so I think
the jack is sticking against the butt. Sure enough, the butt felts
(buckskin?) are graphited heavily. I replaced one with buckskin dusted
with teflon. It stuck even worse than the others. I then put in a
heavier jack spring, and this seems to work, but it gives a heavier
touch. I've seen this problem in other pianos. Some tuners have glued
weights to the whippen, etc. Any ideas?

Thanks,

Philip Jamison
West Chester, PA