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<DIV><FONT face=Arial>Dale,</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>I'm not an expert at wood drying, but I did air-dry my
first couple loads of Sitka that I bought a few years ago. Some of the boards I
have dried were two inches thick and some one inch thick. Whereas I was not able
(no moisture meter) to measure the actual MC of the wood, I found that one-inch
boards could be dried with minimal checking in just a month or so - dry enough
that no additional checking occurred when brought into my 50% RH shop. Drying
times for additional thickness is an exponential function. I had a formula for
it, but can't find it (sorry).</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>With your local 30% RH levels - air drying
without some method to slow the process will likely result in some degree of end
checking (but maybe for crosses, that is not a big issue). My guess is that your
8-inch sections will require at least a year to come down to some
reasonable MC - maybe a lot more - but your low RH is going to move
the process along pretty fast also. Air movement through the stack is also
a BIG factor in drying rate (and also in mold/fungi
growth). </FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Consider also your final construction method. How are you
going to make the cross joint? Are you going to make it flat - i.e. cut a notch
half-way though each timber? If so, then take advantage of Ron's suggestion and
cut the wood into one or two-inch-thick laminations - the criss-cross every
other lamination to make your joint - it will be very strong. And like Ron says,
even if you aren't making the joint flat, cutting into thinner laminations and
then gluing back up will hasten the drying process.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Or are you not going to glue the joint and instead rely on
mechanical fasteners? If so, why even worry about the drying (although I guess
you never know how much it's going to warp). I suppose you could assemble the
cross any time after the darn thing stops dripping!</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>If I were building a big cross, I'd cut one or two-inch
thick laminations and alternate the cross pieces making a flat joint and use
pretty much any type of water-proof glue/adhesive to assemble.</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>Terry Farrell</FONT></DIV>
<DIV><FONT face=Arial></FONT> </DIV>
<DIV><FONT face=Arial>PS: Sorry you and many others were not at NEECSO this past
week/end - a great belly experience was had by all! It was great seeing
David Anderson.</FONT></DIV>
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<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=sec@overspianos.com.au href="mailto:sec@overspianos.com.au">Ron
Overs</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=pianotech@ptg.org
href="mailto:pianotech@ptg.org">Pianotech List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, April 28, 2008 1:11
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Drying large timbers</DIV>
<DIV><BR></DIV>
<DIV>Dale,</DIV>
<DIV><BR></DIV>
<DIV>The rule of thumb is 1 year for every inch of thickness. If you want them
to season faster you may need to break them down into two or three slices,
then glue them together once they've dried. This is why most piano makers
laminate the back post and beams from three or more pieces. It saves them
having a yard full of lumber which they've paid for, but can't use just yet.
Furthermore, the greater the section size the greater the risk of checking
during the seasoning process.</DIV>
<DIV><BR></DIV>
<DIV>Ron O.</DIV>
<DIV><BR></DIV>
<BLOCKQUOTE cite="" type="cite"> Hey all woodchucks<BR>
We hav a project in progress at church which requires air drying
Ponderosa pine. I have section that are 8 inches square. They
were cut green in January & are now stacked and stickered in a barn
drying. Our Humidity levels have been in the mid to upper 30% region. We
will make replica crosses out of them & install them outside. SO how
long will this take?<BR> My guess is by August they should be plenty
dry<BR> What say yee oh wise ones<BR>
Dale</BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>