[pianotech] wippen felt advice

William Truitt surfdog at metrocast.net
Fri Jun 26 16:02:05 MDT 2009


HI Tom:

 

I think you would be most helpful to those of us who want to give you good,
accurate advice if you were to tell us exactly which parts in the action
have been replaced.  New hammers?  New damper felts?  Have the underlevers
been replaced, or are they original?  If they are new, I would particularly
check for too strong damper springs.  If they are original and the felt that
contacts the spoon has not been replaced, you would be astonished how much
friction can come from that interface once the felt reaches a certain amount
of wear.  Along with that, burrs or corrosion on old spoons can add a lot of
friction.  Were the hammer butts replaced, or at least, was the hammer butt
leather replaced.? If not, you have 130 year old butts that are likely
heavily cavitated, again another source of high friction.  And, it may seem
strange, but very loose and worn key bushings can contribute a lot of
friction.  

 

I would say also that you should not be looking for ONE thing as the
problem, particularly if most of the parts in the action are original.  It
may be an accumulation of sins.

 

Will Truitt

 

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of Dean May
Sent: Friday, June 26, 2009 11:46 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] wippen felt advice

 

>>Remember, this thing is ancient! Good luck!

 

Since it has been mostly rebuilt I would suspect it's most likely not a from
old parts, but from new parts, either incorrectly selected parts, or
improperly set up. 

 

Dean

Dean May             cell 812.239.3359 

PianoRebuilders.com   812.235.5272 

Terre Haute IN  47802

 

  _____  

From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf
Of J Patrick Draine
Sent: Friday, June 26, 2009 10:57 AM
To: pianotech at ptg.org
Subject: Re: [pianotech] wippen felt advice

 

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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