Joseph Alkana wrote: > I'm sure this has been covered many times before, I just don't recall seeing > it, but...what is so wrong about just using CA glue to fix the key? There is absolutely nothing wrong with using CA for a repair so long as the repair is done properly. Almost all adhesives work very poorly in tension and very well in shear, so the trick is to use the proper combination of adhesive, reinforcement and geometry to make sure that the strongest, stiffest repair is made, which typically means adhesive acting in shear. Simply butt gluing pieces of a key with any adhesive will be a poor repair, since the adhesive will be acting under tension/compression. Using reinforcing pieces not only provides stiffening material, but makes it possible for the adhesive to act in shear. CA and carbon fiber is a good combo, as is CA and wooden veneer. CA alone on a joint that will not be stressed in tension can also make a good repair. An example of this kind of repair is a break where the wood is splintered along the grain, but not across the grain in a key. Sorry for the longish answer. To summarize, nothing is wrong with CA so long as you use it correctly. Frank Weston
This PTG archive page provided courtesy of Moy Piano Service, LLC