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I think what Dan is trying to describe to you is simply that if the "hole"
wasnt there... then what would happen to the same area of wood around that
hole ? Why should that react differently, or why shouldnt it ? Think about
that as well when you drill your test piece tommorrow. :)
<p>In returning a bit to the starting point for this thread, it seems we
have reached a consensus that this problem about keybeds and lost motion
is probably more related to felt being affected by humidity changes then
to wood related concerns ??
<br>
<br>
<p>Farrell wrote:
<blockquote TYPE=CITE><style></style>
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! Terry Farrell
<br>Piano Tuning & Service
<br>Tampa, Florida
<br><a href="mailto:mfarrel2@tampabay.rr.com">mfarrel2@tampabay.rr.com</a>
<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>
<font size=+0>Terry Farrell wrote:</font>
<blockquote class=cite cite type="cite"><font size=+0>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>
<p><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.
<p><font size=+0>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.</font>
<p><font size=+0>There are some exceptions to this behavior:</font>
<br><font size=+0>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.</font>
<br><font size=+0>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.</font>
<br><font size=+0>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.</font>
<p><font size=+0>Don Mannino RPT</font>
<br> </blockquote>
</blockquote>
<p>--
<br>Richard Brekne
<br>RPT, N.P.T.F.
<br>Bergen, Norway
<br><A HREF="mailto:Richard.Brekne@grieg.uib.no">mailto:Richard.Brekne@grieg.uib.no</A>
<br>
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