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<DIV><FONT face=Arial size=2>Hi Terry and Jude,</FONT></DIV>
<DIV><FONT face=Arial size=2>I'm following this with interest and think I'm
missing something. I can't for the life of me see any weakness, from a strictly
structural standpoint, of any component being laminated. This, I would think,
would only help to increase stability and uniformity. Unless, of course the
adhesive were faulty. Since we are assuming these components will not be below
the water line or subjected to high heat, almost any accepted wood glue should
be fine. I guess sub freezing temperatures should be considered. There is such a
huge area of glue joint, I can't imagine a failure, but, I'm intrigued by your
concern Jude, I hope you will share some of your research. </FONT></DIV>
<DIV><FONT face=Arial size=2>BTW, Jude, I just got a tour of Rick Wheeler's
shop, he say's hi. Loved your piano in Rochester.</FONT></DIV>
<DIV><FONT face=Arial size=2>Fenton</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=juderev@verizon.net href="mailto:juderev@verizon.net">Jude
Reveley/Absolute Piano</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, January 28, 2008 12:41
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: Laminated panels
(Farrell)</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2><STRONG>Hi Terry,</STRONG></FONT></DIV>
<DIV><BR><FONT face=Arial size=2>> Jude - Regarding your concern about
horizontal shearing stress. Is that <BR>> concern that the panel or rib
might fail or degrade in some way as a result <BR>> of whatever shearing
stresses might be present? Is your concern that these <BR>> items might
fail or degrade more readily than a solid item?</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2><STRONG>I think so. When I think of a
composite structural member supporting a floor or a ceiling, I know the
beam is engineered to resist any potential load by a significant
factor. This would be too stiff in a piano sb design, so I would be
concerned that the shearing strain from the string bearing load might be an
issue if not in delamination than checking the cross grain laminations. Then
again, the only problem might be my understanding of the problem and I'm
looking at addressing this presently. Give me some time.</STRONG></FONT></DIV>
<DIV><BR><FONT face=Arial size=2>> <BR>>>From what I've experienced,
building these items with adhesives such as <BR>> Titebond yields excellent
results. Some folks would have concerns regarding <BR>> glue "creep" with
Titebond. I don't, but if one did, build the panel or ribs <BR>> with a
glass-hard adhesive like two-part urea-formaldehyde. Is "creep" where <BR>>
your concern center? I used a modified two-part urea-formaldehyde adhesive
<BR>> on the panel that Richard Brekne wrote about. Certainly the bond with
that <BR>> adhesive is way stronger and sheer-resistant than the wood
itself. And with <BR>> respect to the panel, I should think that crossing
grain angles between <BR>> laminations would also make the entire assembly
more resistant to stress <BR>> from any direction - including
sheer.<BR>> <BR>> Just my thoughts, FWIW.<BR>> <BR>> Terry Farrell
<BR>></FONT></DIV>
<DIV><FONT face=Arial size=2><STRONG>That's a very good and focused question.
I don't think my concern is with the creep but perhaps with the
adhesive. Perhaps I'm just being a nervous Nellie and if the load does not
exceed its demands, we're ok. You also have the advantage of the
assembly being attached at both ends (I have even more concern about a
laminated key that is working as a cantilever, but then the loads aren't so
great here). I'll get back to you when I have a clearer understanding of what
I've read on the subject and have perhaps made some experiments myself. Man I
wish I had some of those cool devices Mr. Hoadley has at
UMass.</STRONG></FONT></DIV>
<DIV><FONT face=Arial size=2><STRONG></STRONG></FONT> </DIV>
<DIV><FONT face=Arial size=2><STRONG></STRONG></FONT> </DIV>
<DIV><FONT face=Arial
size=2><STRONG>Jude</STRONG></FONT></DIV></BLOCKQUOTE></BODY></HTML>