This is a multi-part message in MIME format. ---------------------- multipart/mixed attachment ------=_NextPart_001_0049_01C35E6F.211AEF60 Word document with formula etc. is attached. I think the formula can be = useful for getting some kind on an initial guesstimate of how long to = expect a piece of wood to dry. I don't think it will be very useful for = predicting how fast a soundboard panel will go from 9% MC to 6% MC. I have found the best way to closely monitor wood MC is by weighing = smaller pieces and/or measuring across grain of a panel. I have two = panels in my hot box right now. They've been in there for six days at = about 92 degrees F and 27% RH. They have shrunk 3.5 and 5 mm as of today = and they are still shrinking. What I do is take them down a tiny bit = drier than I want them (if target is 6% MC, I'll go to 5.5% or anything = a little lower than 6%) and then let the RH rise just a tad and make = sure they grow a tiny tad - that way I know for sure the panel had = equilibrated at the lower RH - if it still seems to shrink, go tune = pianos for a week and then go back and check the hot box. Weighing = samples works quite well also - although you always will wonder if the = sample is drying a litte faster because of its increased surface = area/volume ratio, and its increased percentage of end grain. I also found a reference to the two soundboard CLAMP articles: David Hughes soundboard press in PTGJ is August 1993 Clair Davies soundboard press - August, September, October 1997. Terry Farrell =20 ----- Original Message -----=20 From: <BobDavis88@aol.com> To: <pianotech@ptg.org> Sent: Saturday, August 09, 2003 11:24 AM Subject: Formula for rate of change of EMC? > I know a while back someone posted the formula for rate of change of = EMC over=20 > time. It was based on the ambient humidity and the thickness of the = wood.=20 > I've been looking through the archives and through the Wood Handbook, = and I can't=20 > find it. Probably staring right at it. Anyway, will whoever? >=20 > Thanks > Bob D > ------=_NextPart_001_0049_01C35E6F.211AEF60 An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/4d/5c/6b/66/attachment.htm ------=_NextPart_001_0049_01C35E6F.211AEF60-- ---------------------- multipart/mixed attachment A non-text attachment was scrubbed... Name: Air Drying wood.doc Type: application/msword Size: 33893 bytes Desc: not available Url : https://www.moypiano.com/ptg/pianotech.php/attachments/d2/5f/ef/3f/AirDryingwood.doc ---------------------- multipart/mixed attachment--
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