On May 22, 2009, at 2:25 PM, Jim Busby wrote: > All in all I think at fault is the felt, front duplex/design I've been out of town and out of touch, so this is a late entry to the conversation. I'd like to add to what has been said that I have come to believe that friction between strings and underfelt is often if not usually higher than other friction points (like with the agraffe or the capo and duplex bar). Wool felt is often pretty high friction to begin with, and if rust enters the picture things get pretty bad for tuning stability. As a matter of policy, I use powdered teflon on all felt that strings are bearing on, and it helps considerably. Yes, it looks pink (on top of red underfelt), and might not do for "customer rebuild" work, but it's fine for the university. For other customers I'd probably brush on McLube or ProLube on the surface, fairly liberally. Also, firm and relatively thin felt (high quality key bushing cloth) should be used for agraffes, and fairly felt (firmer than butt felt IMO) cut just to height for capos after duplex bars (or half rounds). This means tapering on most Steinways. The strings should just depress a bit of felt, that's all that is needed. It's not a good idea to be liberal with the height, and allow the strings to compress the felt a lot. I like the variety of felt thicknesses provided by Pianoforte Supply, as it means minimal customizing. Regards, Fred Sturm University of New Mexico fssturm at unm.edu -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://ptg.org/pipermail/caut.php/attachments/20090531/b87c5bb6/attachment.htm>
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