----- Original Message ----- From: "Rupert Williams" <obliquestrung at yahoo.com> To: <pianotech at ptg.org> Sent: Wednesday, May 30, 2007 12:12 PM Subject: kneading hammers Greetings Rupert: > Please could someone give some advice on exactly how > to go about kneading hammers as suggested by Alfred > Howe in his book on Scientific Piano Tuning and > Servicing (1947)? That's a catchy title! Can't say I've seen the book (or the movie). :-) > He mentions gas pliers, and kneading in alternate > directions. Others on this group have in the past > explained how they have used vice-grips. Hmm, I'm not familiar with gas pliers, but I do know what vise-grips are. > > I would like to know exactly where to apply the > pressure, and how much pressure to apply. Should the > felt thickness be reduced by 1/2 or some other > fraction? No, I don't think you want to reduce the felt thickness by 1/2 (whew!). In fact, I can't believe that anyone could responsibly say, reduce the felt thickness by "this much." It all depends on the hammer, how hard it is, & what your goals are. When I've used vise-grips, the squeeze has been between, say, 1:30 and 3:00. A small imprint is made on the sides and the hammer surface is slightly cupped. Then I proceed to needle the shoulders until the cupping is gone. This is one method to open up or increase the sustain on hard hammers. > > Can the felt be permanently damaged? Yes. It is quite possible to ruin hammers with Vise-Grips. >Is it inherently more harmful than needling? I wouldn't say so--but yes, if it's over done. It reduces the amount of needling one might need to do to get similar results. I feel the advantage is speed and ease--on the right hammers. Be careful of mis-shaping the hammers. Unless you really know what you are doing, I would be very careful to avoid the strike point or the area below it. In general, tread very carefully. Just because a little works, it doesn't mean a lot works better. Off to work. Good luck! Barbara Richmond, RPT near Peoria, IL
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