[pianotech] Effect of Teflon on damper felts, and VS Profelt on damper wire bushings?

[david at piano.plus.com]

One of my clients has a nice old Bechstein 7' grand.

The combined damper felt noise gives a definite "BUNK" sound (from hard
felt against string, not from pedal mechanism). Fitting new wedge felt to
one of the bichord notes and letting the customer (a Doctor) hear the
difference between it and its neighbour, easily showed her the value of
doing the job. Replacing damper felt is a job I somehow find very
satisfying.

I was just musing, though: When dampers, especially bass ones, sit back
into place, there must be some movement of felt against string, some
"slip".  What would be the effect, if any, of a very light coating of
Teflon powder applied to the bearing surfacces of at least the bicord and
monochord dampers?

Also (and apologies if this has been discussed before), might VS Profelt
be useful for the damper wire guide bushings?

Best regards,

David.