"What would be wrong with preemptively treating all the bridge pins in the whole piano with CA..." I'm not sure how much effect CA will have on a fully assembled newer piano in excellent condition - remember CA has little shear strength - but I think the general idea is a good one. This is why myself, and some others at least, epoxy-treat the bridge pin hole during the pinning procedure of rebuilding. There are different ways to do it, but I swab the bridge pin hole with a length of piano wire dipped in epoxy (I get a couple drops in there). Then I dip the base of the new bridge pin in epoxy and tap it in place. Terry Farrell ----- Original Message ----- > Speaking of CA to fill the gaps around bridge pins, let me make a few > suppositions, then advance a thought. > > 1. Besides filling the gap, the CA also penetrates the wood surrounding > the hole, and then solidifies into a sleeve which is custom-fit to the > pin and its particular hole. So, to the extent the CA adheres to the > pin, it not only corrects the fit, it also locks it into the bridge cap > and root. > > 2. Presumably, the CA we choose to use is as rigid as wood or more so, > and therefore would conduct vibration as well or better (is this true?). > > 3. Because it is a type of plastic, the CA'd bridge resists > humidity-cycle-related dimensional changes better than naked wood would. > > 4. Therefore, besides filling gaps, it seems to me that CA _possibly_ > improves the bridge and cap functionally, above and beyond just > repairing looseness. > > So this all makes me wonder: What would be wrong with preemptively > treating all the bridge pins in the whole piano with CA, before there is > ever a problem, to prevent the development of loose bridge pins and > related possible falseness, tuning instability, and ugly cracking? The > penetration of the glue into the surrounding wood spreads the > side-bearing load into a larger mass, thus reducing ovalling and > improving both dimensional and therefore tuning stability. The enhanced > stability might prevent cracking at the notches from ever getting > started, thus preserving both tone and appearance. > > Has anyone noticed any kind of drawback to the use of CA, especially > tonal, or is its effect always somewhere between zero and positive? > > Inquiringly, > > -Mark Schecter > Oakland, CA > > > John Formsma wrote: > > > > What besides filling gaps would CA do? It wouldn't add mass. > > > -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20060406/4a5e0ddb/attachment.html
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