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<DIV><FONT face=Arial size=2>(Sorry, meant this to go to Mark...which it did,
along with everyone else. Happy New Year! Ed)</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV style="FONT: 10pt arial">----- Original Message -----
<DIV style="BACKGROUND: #e4e4e4; font-color: black"><B>From:</B> <A
title=ed440@mindspring.com href="mailto:ed440@mindspring.com">Ed Sutton</A>
</DIV>
<DIV><B>To:</B> <A title=caut@ptg.org href="mailto:caut@ptg.org">College and
University Technicians</A> </DIV>
<DIV><B>Sent:</B> Monday, December 31, 2007 1:16 PM</DIV>
<DIV><B>Subject:</B> Re: [CAUT] bridge-pin experiment</DIV></DIV>
<DIV><BR></DIV>
<DIV><FONT face=Arial size=2>Hello, Mark!</FONT></DIV>
<DIV><FONT face=Arial size=2>You've got the outline of an article
here.</FONT></DIV>
<DIV><FONT face=Arial size=2>Would you like to develop it and take
photos?</FONT></DIV>
<DIV><FONT face=Arial size=2>Or, would you be willing for me to assign it to
someone, to develop and take photos, then publish with both of you as
co-authors?</FONT></DIV>
<DIV><FONT face=Arial size=2>We have some lab research on false beats being
written into articles. It would be good to publish a repair article when we
publish the research on false beats and bridge pins.</FONT></DIV>
<DIV><FONT face=Arial size=2>Ed Sutton</FONT></DIV>
<BLOCKQUOTE dir=ltr
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=cramer@brandonu.ca href="mailto:cramer@brandonu.ca">Mark Cramer</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A title=caut@ptg.org
href="mailto:caut@ptg.org">CAUT</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Monday, December 31, 2007 12:50
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [CAUT] bridge-pin
experiment</DIV>
<DIV><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Happy New Year to
all!<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">While in <st1:City
w:st="on"><st1:place w:st="on">Banff</st1:place></st1:City> earlier this
month, I made an experiment I’d wanted to try for some time, comparing the
relative penetration of epoxy and CA glue in treating loose
bridge-pins.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">In brief, I installed about a
dozen bridge-pins into sample stock, then twisted them out and re-installed
them to “loosen” the fit. I applied CA to ½ of them, and epoxy to the rest,
with some black dye added, as a “tracer.” <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Note: The epoxy was West System,
and I heated the bridge-pins with a soldering iron (a tip from Joe Garrett
that’s stood the test of time) to help the epoxy penetrate.
<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">The next day I removed the bridge
pins and ripped the stock through the hole-centers to check the results. All
pins were now extremely tight!<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Overall, both products penetrated
the holes to a depth of a1/4” or more, which by Ron Nossaman’s good advice,
should be plenty.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Both products also seemed to fill
the void well, leaving a precise half-mold of the bridge-pin, that is, when
the material hadn’t pulled away with the actual pin.
<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I noticed a little difference in
the two resins however; the epoxy was a solid opaque deposit, while the CA was
more cellular, sometimes with tiny voids or bubbles between. If you’ve used
these products however, you will already be familiar with these
characteristics, and neither seems to suffer in holding ability as a result.
<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">(Secretly, I had been cheering for
the epoxy, on the presumption that the thickness of the resin (once it cooled)
would make a better gap-filler in the long term.)<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I used a 20X jeweler’s loop to
examine, and no, I didn’t take photos.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">In terms of application, the CA
was the winner. Using a syringe, it’s possible to mete out thin CA very
precisely; watching it disappear around the pin, then adding more. If you
overdo it a bit, it can easily be drawn back into the syringe, leaving a very
tidy, clean surface. (We’ve frequently taken advantage of this property to
treat bridge-pins with strings in place) <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">The epoxy however, seemed to leave
a small collar around the base of the pin. With practice, I was able to get
the collar small enough that it wouldn’t contact my test-string (#16 wire),
however, I don’t know if I would have the courage to apply epoxy with strings
in place.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">In conclusion, this wasn’t a very
scientific experiment, but it was about all I had time for, and it answered my
questions just fine.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">As a result, we will continue to
use thin CA to treat loose bridge-pins, with strings in place. The application
is easy, the results (correcting false beats) have been good, and now we know
the glue is making it well below the bridge surface. BTW, I still believe it’s
better to saturate one pin at-a-time, then doing a whole section in a series
of passes, at a risk of “sealing” the hole on the first
pass.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">For re-pinning a bridge, we’ve
been using Bill Spurlock’s epoxy method (PT Journal, March 1992) for over a
decade and will not change a thing. Joe Garrett’s method however, is still the
best I can think of when you have to re-use a bridge-cap that needs some
reconditioning, especially when they start to get tiny splits and visible
voids.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Now here’s a challenge I’ve
perhaps thrown down before:<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">If you’ve never tried to deal with
false beats, (or are holding to some noble albeit untested notions ;>) why
not treat yourself to a rewarding little
experiment?<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">The next time you’re tuning an old
practice-room grand and encounter a false beat, isolate the string (by muting
the other two) then gently rest a screwdriver on the forward bridge pin and
see whether the false beat stops. If so, you have a
candidate.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">If you want to experiment with the
string in place (and why not…you’re the same person who has to fix it :>),
test your syringe technique outside the piano first, then carefully apply CA
to the base of the pin, on the non-string side. Apply drop-by-drop, wait and
watch, then continue until the pin won’t take anymore. Withdraw any excess
glue with the syringe. <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">I would actually wait awhile
before tuning, as we don’t know how long the glue takes to cure below the
surface, however you can likely go back in an hour or so and simply “listen”
to the results. As mentioned earlier, we’ve been using this method for several
years, with good success.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Best
wishes,<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><st1:PersonName w:st="on"><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Mark
Cramer</SPAN></FONT></st1:PersonName><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">,<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><st1:place w:st="on"><st1:PlaceName w:st="on"><FONT
face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Brandon</SPAN></FONT></st1:PlaceName><FONT
face=Arial size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">
<st1:PlaceName
w:st="on">University</st1:PlaceName></SPAN></FONT></st1:place><FONT face=Arial
size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <o:p></o:p></SPAN></FONT></P></DIV></BLOCKQUOTE></BODY></HTML>