Ron I find that with tight bond glue it takes about 3 days for the glue joint to get quite hard & then the boom really comes alive. With the Bolduc glue it's the next day. > and is there any advantage to trying to make that rim > immoveable, and is there a consequence to it moving with respect to the > soundboard? Another recent observation along these lines, for anyone interested. I've read for years how a soundboard doesn't boom much when it's first glued in, and develops a boom after a few days. With the RC&S board I put in the B I'm currently trying to get done, I was playing with the boom, or ring tone of the board to see what it did. With the F clamps just on, and Titebond still dripping on the floor, I thumped the mid tenor bridge with my fist. Got a good solid boom with a bit over three second ring time! Thump tone changed frequency up and down scale just as I'd expect, but the ring duration really stood out as extraordinary. Next day, I removed the clamps and thumped it again. Still a good boom, but the ring time was half of what it was before I took off the clamps. Now, "conventional wisdom" would say it had "something" to do with the fit at the rim, and the clamps supplying added coupling between the panel and rim, but that ain't it. As I was leaning on the curved side pounding away, it struck me that the rim was vibrating like a palm sander against my stomach, which wasn't nearly as dramatic with the clamps on. Even with that "iron fortress" rock maple rim, it was absorbing more soundboard energy because I had removed the MASS of the clamps from the rim. When I got the plate bolts installed, the plate in, and tightened down the cap nuts, the board ring time came right back courtesy of the plate mass. Sooooo, it seems to me that this could be something else to add to our arsenal of possible field modifications in our never ending quest to make pianos seem better than they were either designed or built to be. Addition of mass loads to inner rims to improve sustain in otherwise functional soundboards should be worth a try in some situations. It would be easy enough to clamp on test loads to diagnose problems and potential improvements, and quick and cheap enough to implement if it helped and you had a need. To whomever, Ron N -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20060415/8c347faf/attachment.html
This PTG archive page provided courtesy of Moy Piano Service, LLC