This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment ----- Original Message -----=20 From: Richard Brekne=20 To: Pianotech=20 Sent: August 18, 2003 10:38 AM Subject: Re: More on soundboard crown Now correct me if I am wrong.. but I understand this to mean that a CC = board will be stiffer, both unstrung... and increasingly so when = downbearing is applied. Assuming that is correct,=20 Which it is not. and putting aside all other compression damage discussion for a second = or two... I have a question about this long term so called compression = set.=20 By this are you implying you don't believe the phenomena exists? Check = The Wood Handbook (USDA) and Understanding Wood (R. Bruce Hoadley). Given the absolute ideal climatic conditions over many years... would = a soundboard subjected to uniform compression set take on a permanent = stiffness as a result of that, or is it exactly the woods resistance to = being compressed that causes the stiffness ? Seems to me I also read = something in one of Johns posts that hinted in this direction. That a CC = board <<properly treated>> will eventually be pressed into a very stiff = and permanent condition.=20 No. Compression set continues until some neutrality is reached. I.e., = the point at which there is so little compression left within the panel = that in practical terms the wood fibers no longer deform. At this point = compression and crown and stiffness will be at their minimum point.=20 On the side of this... and please forgive whatever lack of knowledge I = display in the asking, if compression from ribs being glued cross grain = to the panel is such a problem...even in RB boards.. is there no way of = contriving a rib such that it is a bit less constraining ?=20 I don't understand any part of this paragraph: -- What compression from the ribs? In a compression-crowned = soundboard system the compression is in the soundboard panel, not the = ribs. The rib-crowned system uses an entirely different technology that = has been described in infinite detail numerous times in print and on = this list. -- Compression from ribs is not a problem. -- Ribs, in a rib-crowned system, can be contrived to do just about = anything you want them to do. -- What do you mean by "less constraining?" Del ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/f8/27/2e/4e/attachment.htm ---------------------- multipart/alternative attachment--
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