What Dale said. Support jack? A pinblock support jack? I'm having trouble visualizing how a pinblock support jack could cause the plate to crack. You reference "releasing" the jack. What type of jack is it? I'm only familiar with screw-type pinblock supports. When you put the pinblock support in place, I guess I've never been instructed one way or another, but I just snug it in - I don't jack the pinblock up at all. So if the jack didn't move the block, and hence the plate, and then you remove the support with tension on the strings, okay, so the plate/block will adjust some tiny little bit, but why would it cause a crack? Seems to me the plate would be in that position anyway and would be experiencing whatever stresses it does either way. I just don't see how removing a pinblock support would cause the plate to crack. Thoughts? Terry Farrell ----- Original Message ----- Check the Archives for www.Lock-n-Stitch.com. Been lots on it Dale Erwin -----Original Message----- I have a Chickering 1/4 grand in the shop with a hairline crack on the treble strut between the two capo sections. This is right where a nose bolt passes through, so the crack extends from the top of the strut to about halfway through. I'm sure it was my error that caused the crack. (I restrung the piano, chipped it, and had it up to pitch before realizing that I still had my support jack in the high treble. With all the string tension, it was really wedged in. It was very difficult getting it to release and when I released the jack, I heard the crack. SNIP Gordon Large, RPT -------------- next part -------------- An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/20080402/31e94419/attachment.html
This PTG archive page provided courtesy of Moy Piano Service, LLC