[pianotech] wippen felt advice

[J Patrick Draine]

I'm sure Pianotek or Pianoforte can provide you with acceptably firm cloth
for the wippen pads. The worn key bushings could be causing wobbling between
the dowel capstan and the wippen cloth, wasting pressure on the key on side
to side friction rather than direct wippen movement.Even though the various
flanged parts appear to  be free of verdigris and "move freely", remove them
from one of the "high friction keys", and take some measurements of flange
friction. What condition is the hammer butt buckskin and butt felt? Damper
lever felt at spoon contact?
Remember, this thing is ancient! Good luck!
Patrick

On Thu, Jun 25, 2009 at 7:27 PM, Tom Sivak <tvaktvak at sbcglobal.net> wrote:

> List
> The piano is a Steinway upright from the 1870s. It came to me, refinished,
> almost completely rebuilt, and nearly unplayable.  There is a lot of
> friction, especially on some keys.  I suspected verdigris, but the action
> centers were not the problem.  (It is verdigris free, and everything moves
> freely.)
>
> The problem seems to be the wippen pads.  The hammer moves with no
> appreciable resistance when I lift the wippen with my finger.  Push the key
> down and I have to use undue pressure.   The keys themselves need new
> bushings, move too freely, and are not the problem, either.
>
> The capstans are smooth and when I run my finger over the top there is no
> stickiness, roughness, or anything would increase friction.  (They are the
> big wooden dowel capstans.)
>
> The wippen felt pads, though, are heavily dented, even though they were
> replaced in the rebuild.  They are a white felt, they look to be an
> appropriate thickness, but my theory is that the felt was too soft and thus
> the dents are, at least, a part of the problem.
>
> I want to make sure I don't replace these with a felt that is also too
> soft.  How can one measure and compare the softness of felts?
>
> Or is there a specific brand/weight/etc. that you have used with success?
>
> Thanks in advance for any advice you all might have,
>
> Tom Sivak
> Chicago
>
>
>
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