At 12:14 PM 12/21/2002 -0500, you wrote: >"but I wonder about the permanent damage from over drying. What's your >source on that?" > >I looked, looked and looked, but could not find it. Somewhere I read, and >I think it may have been you that posted a link to a 1923 (or so) study on >the strength of sitka spruce for airplane use (maybe it was someone else). Yup, that was me. > A large part of that paper reported on how different drying methods > affect wood strength. I'm quite sure it was in there that it said that if > you oven dry the wood to zero MC, you will destroy it's further use for > MC - I think I just assumed that it would affect its other > characteristics also. That was about drying Spruce from green to usable MC without having to wait years for air drying. The war demanded a higher production rate than was then available by conventional methods, and they were trying to shorten the drying cycle without ruining the wood for it's intended use. I don't recall anything about drying below a usual working MC for airplane construction, just data on drying too quickly, with too much heat. I've spent some time looking, and don't recall having seen anything anywhere about damage resulting from drying to zero% MC. Unless, of course, excess heat is used. I've heard it stated as fact a few times, but haven't seen any reasonably credible reference to that effect. If such a reference exists, I'd appreciate knowing about it. >The other post indicated "as low as possible" - that would be zero MC. I >suppose in practice someone drying a panel "as low as possible" means more >like "pretty low" and perhaps not zero MC. But hey, I saw what I saw and >read what I read. I take folks at their word......unless otherwise inclined. > >Terry Farrell And I agreed. Ron N
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