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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=davidlovepianos@earthlink.net
href="mailto:davidlovepianos@earthlink.net">David Love</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A =
title=pianotech@ptg.org
href="mailto:pianotech@ptg.org">Pianotech</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Wednesday, March 19, 2003 =
1:49
AM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Soundboard =
varnishes</DIV>
<DIV><BR></DIV>
<P><FONT face="MS Sans Serif" size=2>
<DIV>First, what differentiates the type of varnish used on violins =
and cellos
from the spar varnish often used on pianos. I notice that =
the
varnish on violins is quite hard, even brittle, whereas spar =
varnishes
are typically a bit rubbery (have I answered my own question?). =
What is
the composition of violin varnishes, typically--I know, for =
Stradivarius it
was a secret. How might this difference effect tone on a
soundboard. And, is there a reason to select a very =
hard,
even brittle finish? </DIV>
<DIV><FONT face=Arial size=3></FONT> </DIV>
<DIV>Second, are there potential ill effects from putting too heavy a =
coat of
varnish on a board. Can too heavy a coat of rubbery spar =
varnish
actually impede sound transmission through the board, and how thick =
would it
have to be to create a problem. </DIV>
<DIV><FONT face=Arial size=3></FONT> </DIV>
<DIV>Third, can varnish effect epoxy underneath
it? </DIV>
<DIV><FONT face=Arial size=3></FONT> </DIV>
<DIV><FONT face=Arial size=3>I'll take this one, since I am a =
violin
maker. Violins usually have one of two kinds of varnish, spirit =
or
oil. The discussions of the merits of each have been going on =
for
hundreds of years. Spirit varnish is alcohol soluble and =
infinitly
short since all the solvent evaporates. I'll concentrate =
on oil
varnish because I prefer it. Varnishes are classified as =
short or
long depending on oil content. Less oil, more resin is shorter. =
Short
oil varnishes are harder and polish out better. There is an =
infinite
range of hardnesses depending on this ratio. Also oil =
varnishes
can use synthetic or natural resins. Violin makers prefer =
natural
resins, (Since this is obviously what the early makers used). =
Many
violin makers experiment with making their own varnish. Entire =
books
have been written on this subject. Violin varnish may use =
any of
dozens of natural resins, any of several drying oils ( walnut, tung, =
linseed),
and sometimes metallic driers. Violin makers discussing varnish =
is
similar to piano techs discussing temperments.</FONT></DIV>
<DIV><FONT face=Arial size=3></FONT> </DIV>
<DIV><FONT face=Arial size=3>Too much varnish on a violin is akin =
to wrapping
it tightly in a coat of leather. It dampens the =
vibrations. But
some damping is good. How much is good?..... Who knows?. =
If I
could achieve depth of color in two thin coats (rubbed out) I would be =
satisfied.</FONT></DIV>
<DIV><FONT face=Arial size=3></FONT> </DIV>
<DIV><FONT face=Arial size=3>Epoxy is frowned upon in violin =
making, so I
can't say how varnish affects it. What does react with dried
epoxy? Linseed oil and resin don't harm hide glue.</FONT></DIV>
<DIV><FONT face=Arial size=3></FONT> </DIV>
<DIV><FONT face=Arial size=3>I hope this helps, it's a deep
subject. If there are any questions I'll try to answer
them.</FONT></DIV>
<DIV><FONT face=Arial
size=3>Gerald</FONT></DIV></FONT></BLOCKQUOTE></BODY></HTML>