Hi All,  I am doing the final adjustments on my Duo-Art grand stack
push rods so they are in the correct vertical position to meet the key
tails.  When I put the nuts on the pushrods several months ago the nuts
were quite tight and could just be twisted on by hand.  (I had to drill
(enlarge) all the leather nut holes from the supplied hole size so they
would thread onto the push rods.)

Now that they have been on the threads for some time it seems that they
have become looser.  I can hold a push rod from turning with a pair of
leather faced pliers and rotate the leather nuts by hand while
everything is in place under the piano.

How tight do the nuts have to be to prevent them from turning later
while the player is playing, and how do you describe how tight this
is?

If they are too loose, what can be used to make them grip the pushrod
tighter but not completely prevent future adjustment?  Maybe thinned
PVCE?

Thanks,
Pat DeWitt
Fort Wayne, Indiana