Thank you all for the great advice. And Dean, your email in particular reminds me that many times a big problem is caused by many little things. You've all given me some things to try out to further narrow this down. No appointments tomorrow, so I'll have time to play around with it, and hopefully, come to a conclusion. Tom Sivak --- On Fri, 6/26/09, Dean May <deanmay at pianorebuilders.com> wrote: From: Dean May <deanmay at pianorebuilders.com> Subject: Re: [pianotech] wippen felt advice To: pianotech at ptg.org Date: Friday, June 26, 2009, 3:34 PM Is the key resistance throughout the stroke, or only at the end? If at the end look for things that are binding, like damper wires against the stop rail, balance rail pin against the back of the slot, felt square on jack hitting catcher. Just because you don’t perceive excess friction by lifting the wippen, I find that to be a very unreliable test. Disassemble the parts and test flanges individually. Check the depth of balance rail mortise in key Sometimes you’ll get excess friction with bad bushings/pins, so even though they may be sloppy, you’ll still feel excess friction with slight sideways pressure on the keys. Test damper spring tensions with a Correx gram gage. Usually 20-30 grams is more than adequate, measured at damper head. If it silences the string it’s enough. Try holding damper off the string to see how that affects key resistance. Make sure hammer springs aren’t binding or too strong. Try removing hammer spring to see how that affects key resistance. Check jack spring tension. They may have replaced hammer or damper or jack springs with springs excessively stiff. I would not recommend the use of DAG that someone recommended. Use Teflon powder instead. I have often suspected the wippen cloth like you, but have always found something else to be the culprit. 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 Tom Sivak Sent: Thursday, June 25, 2009 7:27 PM To: pianotech Subject: [pianotech] wippen felt advice 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 -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/pianotech.php/attachments/20090626/a7977c59/attachment-0001.htm>
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