[pianotech] clunking upright stickers

[David Nereson]

    Thanks for all the replies on mating grand hammers to 
strings.
    Now I have a piano teacher's old upright whose 
stickers/wippens clunk pretty loudly when returning.  If I hold 
down the back of the keys in question, and lift the wippen and 
let it drop, I hear the clunk.  Depressing and releasing the key 
also clunks, sometimes just as loudly, sometimes not.  I tried 
replacing the sticker cloth with brand new medium thick action 
cloth.  Still clunks.  Tried replacing the sticker cloth with 
hammer skiving felt about 1/8" thick and that was slightly 
quieter, but not much.  Tried re-pinning the wippen flange. 
Still clunks.  Grabbed both the sticker and wippen 
simultaneously, trying to move them apart and away from each 
other, testing the sticker-to-wippen pinning for any play, and 
didn't feel any.  The action has been regulated (no lost 
motion).  And it's not clicks from missing butt felts.
    Now, there's some other minor clunking from balance holes 
that are slightly "pulley," and from key bushings that could 
stand to be replaced, but again, when holding the key still and 
raising & releasing the wippen, I still get the noise.
    I told her there's always a little noise in the action, and 
it can't be eliminated 100%, but these "clunks" seem excessively 
noisy and are noticeable even with all the front case parts in 
place.
    --David Nereson