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<DIV><FONT face=Arial size=2>Terry,</FONT></DIV>
<DIV><FONT face=Arial size=2> I don't make bridge roots but I
do a lot of research on glue and it's effects on wood to try and improve my more
complex key repairs and recovering. First of all:</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>1. What type of glue did you use, PVA? if so, too
much moisture, it takes a very long time for this type of glue (with a lot of
water content, upwards of 60%) to dissipate from the wood and the
curve will continue to change as this happens.</FONT></DIV>
<DIV><FONT face=Arial size=2>2. Thinner laminations (18 laminations) actually
add more moisture to the joint because there are more joints to apply glue
to.</FONT></DIV>
<DIV><FONT face=Arial size=2>3. How were your laminate surfaces prepped?
Jointed, bandsawed, sanded, hand planed? </FONT></DIV>
<DIV><FONT face=Arial size=2>4. Did you heat the laminates, heat if possible
will accelerate drying time which will prevent some of the warping due to time
lapse as the moisture flashes off.</FONT></DIV>
<DIV><FONT face=Arial size=2>5. Urea, polyurethane, epoxy and resorcinol glues
have good creep, rigidity and are more than strong enough for bending laminates.
The biggest plus is that they don't have the high moisture content that
temporarily haunts all glue joints.</FONT></DIV>
<DIV><FONT face=Arial size=2>6. The Glue Book by William Tandy Young (Published
by The Taunton Press) has a chapter on laminates and veneering which is a wealth
of knowledge, for cheap money.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>These are just my thoughts and opinions, I don't
claim to be an authority on laminating bridge roots, by the way, what the hell
is a bridge root? Must be something you belly people make. Good
luck, Mike</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Michael A. Morvan<BR>Blackstone Valley
Piano<BR>Dedicated To Advancing The Art Of Keyboard Restoration<BR>76 Sutton
Street<BR>Uxbridge, Ma. 01569<BR>(508) 278-9762<BR><A
href="mailto:Keymaestro@verizon.net">Keymaestro@verizon.net</A><BR><A
href="http://www.pianoandorgankeys.com">www.pianoandorgankeys.com</A>
<BR></FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2></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=mfarrel2@tampabay.rr.com
href="mailto:mfarrel2@tampabay.rr.com">Farrell</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=pianotech@ptg.org
href="mailto:pianotech@ptg.org">pianotech@ptg.org</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, September 05, 2007 1:44
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Bridge Root Spring-Forward</DIV>
<DIV><BR></DIV>
<DIV><FONT face=Tahoma>Question for those who are in the habit of laminating
up new bridge roots - or maybe even those who don't, but might have some
thoughts to share. I just completed building a bridge root for a customer that
came out very nicely, but the overall curve of the bridge is off by a
couple millimeters or so, much like other ones I have built in the
past. I really don't understand that. </FONT></DIV>
<DIV><FONT face=Tahoma></FONT> </DIV>
<DIV><FONT face=Tahoma>One would think of the possibility of some small
spring-back effect (but with 18 laminations?), but the curve error is always
toward a tighter curve. How can that be? </FONT></DIV>
<DIV><FONT face=Tahoma></FONT> </DIV>
<DIV><FONT face=Tahoma>I don't think it is a significant issue as you can
easily correct the bend with your pinky - but still, how does this
happen?</FONT></DIV>
<DIV><FONT face=Tahoma></FONT> </DIV>
<DIV><FONT face=Tahoma>A couple pics for your viewing pleasure:</FONT></DIV>
<DIV><FONT face=Tahoma></FONT> </DIV>
<DIV><IMG alt="" hspace=0 src="cid:00d001c7f014$23f66170$2f01a8c0@MCO2376"
align=baseline border=0></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><IMG alt="" hspace=0 src="cid:00d101c7f014$23f66170$2f01a8c0@MCO2376"
align=baseline border=0></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><IMG alt="" hspace=0 src="cid:00d201c7f014$23f66170$2f01a8c0@MCO2376"
align=baseline border=0></DIV>
<DIV><FONT face=Tahoma></FONT> </DIV>
<DIV><FONT face=Tahoma>Terry Farrell<BR>Farrell Piano</FONT></DIV>
<DIV><FONT face=Tahoma></FONT> </DIV>
<DIV><FONT face=Arial size=2><A
href="http://www.farrellpiano.com">www.farrellpiano.com</A><BR><A
href="mailto:terry@farrellpiano.com">terry@farrellpiano.com</A></FONT></DIV></BLOCKQUOTE></BODY></HTML>