This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Robin, Do you think if I did some tests on pieces of bushing cloth, I'd be able = to tell anything? I was thinking in particular about the 90/10 acetone/ = CA mix and also trying out some with a bit of methyl alcohol mixed in, = too. Does anybody know if I'll blow up or pass out or anything? (That = last one is the important one, I'm not a chemist.) I repinned some again yesterday, following very precise directions by = folks who should know. I was more aggressive in my burnishing and = working the flanges and just generally pinning tighter, but by this = morning, they had loosened some (I measured each step using my gram = gauge). The flanges went from too tight before working the flange, to = the high end of being acceptable after working the flange. This morning = they were at the low end of acceptable--which is OK as long as they stay = there, but I have a funny feeling they won't stay there for long. After = this test of my pinning technique, I have come to the conclusion that = perhaps I'm not totally incompetent after all----maybe just = partially.... :-) =20 Barbara Richmond ----- Original Message -----=20 From: Robin Hufford=20 To: Pianotech=20 Sent: Monday, December 06, 2004 1:31 AM Subject: Re: Rebushing centers Hello Barbara, I think it is vital to properly shrink and stabilize the = bushings after installation. Otherwise, you will be where you are now = with the inadequate Steinway parts (something ridiculous and telling in = itself for a company in business doing this for 150 years,) you refer = to in recent posts, that is, the friction will not be stable and the = hammer will also wobble causing a loss of power. =20 I have used shrinking fluid combinations with proportions ranging = from 50/50 to 75/25 or so, water and methyl alcohol and had good = results. Although, I have had, on occasion, a need to do some over, as = some were still, after drying, loose. These were then rendered = acceptable after another treatment. =20 An interesting new possibility, which had occurred to me one day = as I was waiting for a conventionally treated set to dry and is, as far = as I can tell, a completely new technique since I have not seen it = referred to anywhere or heard any discussion about it elsewhere, I = decided to try on a set of Tokiwa shanks which had a very soft, = unstable bushing that responded to pining exactly as you describe with = the Steinway, is, perhaps, better. =20 This method uses water thin CA glue thinned even further to = about about a 90/10 acetone/glue mix. It occurs to me now, as I write = this, that it may work better if a little methyl alcohol is added as a = wetting agent, if possible, although I haven't done this. There may be = complications if alcohol is used which I am unaware of at the moment.=20 As you know, of course, the CA rapidly sets and this = characteristic obviates the need for the prolonged drying necessary when = using water. One can vary the mixture as desired to control its = effects, but if too much CA is used it will make the bushing so hard = that it will click and this defeats the purpose of its use. Too little = and there is not enough stability induced in the bushing. =20 On the piano I tried this on I have had very good results; the = pining is stable and there was a noticeable increase in power. I tried = at first to apply it simply by dripping the mixture onto the bushing: = this does have an effect, but, eventually, I removed the pining, wetted = the bushing and then reinstalled a pin. Perhaps, as I indicated = above, a wetting agent like methyl alcohol will make it possible to do = this without even removing the pining. All of the flanges on this = piano had already been repinned, some twice or even three times. They = had progressively loosened as you described earlier. =20 Judging from your recent posts you are considering rebushing = the inadequate Steinway shanks you have referred to. I would try this = technique before rebushing were this problem one I had to solve. I = think, once resigned to rebushing, you have nothing to lose. =20 Regards, Robin Hufford=20 ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/c8/18/5f/9c/attachment.htm ---------------------- multipart/alternative attachment--
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