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<DIV>I'm trying to figure out why a piece of wood is not behaving =
itself.</DIV>
<DIV> </DIV>
<DIV>On 11/6/02 I cut a piece of spruce out of an old soundboard and =
sanded the
finish off. It weighed 91.71 grams. Environmental conditions in my =
shop,
where the soundboard had been for months were pretty constant at 75<FONT =
face="WP MathA">E</FONT>F and 45% relative humidity (RH). According to =
Dept. of
Forestry data, wood under those conditions should have a moisture =
content (MC)
of about 8.4%. </DIV>
<DIV> </DIV>
<DIV>I dried the spruce in my kitchen oven to zero MC =
(monitored
weight periodically until no change was noted for about an hour). The =
oven
temperature cycled from 210<FONT face="WP MathA">E</FONT>F to 250<FONT =
face="WP MathA">E</FONT>F (set the oven to 225<FONT face="WP =
MathA">E</FONT>F)
during the four-hour drying process. When dry, the spruce weighed 84.55 =
grams.
Working backwards to calculate the MC before drying indicates the wood =
was at
8.47% MC - real close to what the Forestry data suggested it would be. =
OK so
far.</DIV>
<DIV> </DIV>
<DIV>I took the spruce out of the oven at zero MC and set it in the shop =
and
periodically weighed it and calculated MC. Last night, after three weeks =
of
regaining moisture in my shop, the spruce weighed 89.80 grams. This =
calculates
out to a MC of 6.21%. Three days ago, the wood weighed 89.76 grams, or a =
MC of
6.16%. Clearly, the rate of moisture accumulation in the wood has almost =
leveled
off. Not OK now.</DIV>
<DIV> </DIV>
<DIV>The shop has been consistently at a temp of 65<FONT
face="WP MathA">E</FONT>F and RH of 45% for weeks now. That should =
equate to a
MC of about 8.5%. I find it hard to imagine that my little piece of =
spruce will
gain enough moisture in my lifetime to get back up to 8.4% or 8.5% =
MC.</DIV>
<DIV> </DIV>
<DIV>Anybody have and great ideas of why the wood seems to be staying =
dryer
after the cooking process? Is 250<FONT face="WP MathA">E</FONT>F too =
hot - has
it changed the wood somehow so that it can't hold as much water? It =
looks the
same. What is going on? Anyone know a professor of wood =
technology?</DIV>
<DIV> </DIV>
<DIV>Under what environmental conditions do commercial wood drying =
kilns
operate?</DIV>
<DIV> </DIV>
<DIV>Thanks.</DIV>
<DIV> </DIV>
<DIV>Terry Farrell</DIV>
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