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<DIV>Your position is consistent with many others. It is likely I who is =
hard/thick headed. I just may go out to the shop tomorrow morning and =
drill me a
hole in some maple and see what happens. Just does not make sense to =
me.
:-) I'll report back!</DIV>
<DIV> </DIV>
<DIV>Terry Farrell<BR>Piano Tuning & Service<BR>Tampa, Florida<BR><A =
href="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</A></DI=
V>
<BLOCKQUOTE
style="BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px; PADDING-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>
<A href="mailto:DonMannino@mediaone.net" =
title=DonMannino@mediaone.net>Donald
Mannino</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A =
href="mailto:pianotech@ptg.org"
title=pianotech@ptg.org>pianotech@ptg.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, January 01, 2001 =
10:56
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: moisture in wool =
or
wood.</DIV>
<DIV><BR></DIV><FONT size=3>Terry Farrell wrote:<BR>
<BLOCKQUOTE class=cite cite type="cite">I have heard/read this =
many times,
so I suppose it is true. But, intuitively, it makes no sense to me. =
If you
drill a hole in a piece of wood and expose it to high humidity, the =
wood
will swell - and swell much more across the grain (perpendicular to =
the
grain direction) than with the grain. So why doesn't the hole tend =
to close
a bit - on the two sides of the whole where the tangents are =
parallel to the
wood grain.</FONT></BLOCKQUOTE><BR>Because the whole piece of wood =
swells, and
the hole becomes larger along with the piece of wood. As I wrote =
in my
last post, imagine the plug of wood which used to be in the =
hole. The
hole behaves the same as the plug of wood that was taken =
out.<BR><BR><FONT
size=3>Do the hole and rod test. Just pick a small piece =
of maple
or something, soak it in water for a while, then drill a hole in =
it with
a spare drill. After drilling, put the drill back in the hole, =
then dry
the wood in the oven! That drill will be really nasty tight in =
the
hole! You'll have to soak the wood again to get it =
out.<BR><BR>There are
some exceptions to this behavior:<BR>1. In some situations the surface =
fiber
swelling in the hole exceeds the change in shape of the wood. =
Key
balance holes are examples of this, where high humidity sometimes =
tightens the
fit. The wood thickness is small, and the wood fibers are large =
and
sometimes made of more reactive wood.<BR>2. Cross-laminated wood is =
more
dimensionally stable, and the surface fibers will again have more =
affect on
the hole size than the dimensional changes of the wood. This is =
what
happens in pinblocks.<BR>3. If the hole was made by compression of the =
fibers
instead of by drilling and removing wood (like with a nail) then the =
grip on
the nail is tighter during humid times. All surface fiber =
effect, no
hole to swell.<BR><BR>Don Mannino =
RPT<BR><BR></BLOCKQUOTE></FONT></BODY></HTML>