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Aaaahhh, NOW I understand. Had problems due to language misunderstandings. Thank you very much, Terry.<br><br>Gregor<br><br><blockquote><hr>From: mfarrel2@tampabay.rr.com<br>To: pianotech@ptg.org<br>Subject: Re: Epoxy Bass Bridge Repair<br>Date: Sat, 10 May 2008 21:00:30 -0400<br><br>
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<div><font face="Arial"><em>Sorry, but I still don´t understand that statement. A
thin layer of Epoxy to remain in the joint? Of which joint you are talking
about: the joint of Epoxy and wood?</em></font></div>
<div><font face="Arial"><em></em></font> </div>
<div><font face="Arial"><font size="3">That's okay - we'll poke away at it
until you do understand! ;-)</font></font></div>
<div><font face="Arial"><font size="3"></font></font> </div>
<div><font face="Arial"><font size="3">All that I was trying to point out is that
most glues (like Titebond) work best with a close-fitting joing - two wood faces
that meet nice and flush with one another - when they are clamped together, you
want significant clamping pressure and most of the glue to squeeze out. With
epoxy, you want just the opposite - the two faces of wood to be bonded together
need not fit together perfectly (in fact better is the joint is a little rough
or jagged) and when you clamp, the clamps are just to hold the two wooden faces
in position - not to apply pressure to squeeze the epoxy out - you want to leave
some epoxy in the joint between the two wooden faces to be
bonded.</font><br><br><em>What does it mean for practice? Should I first apply a
little bit of Epoxy to the wood, let it become hard, and then apply the Epoxy
with the filler?</em></font></div>
<div><em><font face="Arial"></font></em> </div>
<div><font face="Arial" size="3">No. Read on the West System web site about their
two-step bonding process:</font></div>
<div><font face="Arial" size="3"></font> </div>
<div><font face="Arial" size="3">
<font color="#800000" face="Arial" size="3"><strong>Two-step
bonding</strong></font><BR>
<div align="left">
<table border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td align="left" valign="top"><font color="#800000" face="Arial" size="3">1. Wet-out
bonding surfaces-Apply a neat resin/hardener mixture (without fillers) to
the surfaces to be joined (Figure 9). Wet out small or tight areas with a
disposable brush. Wet out larger areas with a foam roller or by spreading
the resin/hardener mixture evenly over the surface with a plastic
spreader. You may proceed with step two immediately or any time before the
wet-out coat reaches the final cure stage.<br><br></font></td></tr>
<tr>
<td><font color="#800000"><img src="http://www.westsystem.com/images/use-09.gif" border="0" hspace="10" vspace="10"> <img src="http://www.westsystem.com/images/use-10.gif" border="0" hspace="10" vspace="10"></font></td></tr>
<tr>
<td align="left" valign="top"><font color="#800000" face="Arial" size="3">2. Apply
thickened epoxy to one bonding surface. Modify the resin/hardener mixture
by stirring in the appropriate filler until it becomes thick enough to
bridge any gaps between the mating surfaces and to prevent "resin-starved"
joints. Apply enough of the mixture to one of the surfaces, so that a
small amount will squeeze out when the surfaces are joined together with a
force equivalent to a firm hand grip (Figure 10).<br></font>
<font color="#800000" face="Arial" size="3">Thickened epoxy can be applied
immediately over the wet-out surface or any time before the wet-out
reaches its final cure. For most small bonding operations, add the filler
to the resin/hardener mixture remaining in the batch that was used for the
wet-out. Mix enough resin/hardener for both steps. Add the filler quickly
after the surface is wet out and allow for a shorter working life of the
mixture.<br><br></font><BR></td></tr>
<tr>
<td align="left" valign="top"><font color="#800000" face="Arial" size="3">3. Clamp
components. Attach clamps as necessary to hold the components in place.
Use just enough clamping pressure to squeeze a small amount of the epoxy
mixture from the joint, indicating that the epoxy is making good contact
with both mating surfaces (Figure 11). Avoid using too much clamping
pressure, which can squeeze all of the epoxy mixture out of the
joint.<br><br></font></td></tr>
<tr>
<td><font color="#800000"><img src="http://www.westsystem.com/images/use-11.gif" border="0" hspace="10" vspace="10"> <img src="http://www.westsystem.com/images/use-12.gif" border="0" hspace="10" vspace="10"></font></td></tr>
<tr>
<td align="left" valign="top"><font color="#800000" face="Arial" size="3">4. Remove
or shape excess adhesive that squeezes out of the joint as soon as the
joint is secured with clamps. A wooden mixing stick with one end sanded to
a chisel edge is an ideal tool for removing the excess (Figure
12).</font></td></tr></tbody></table></div></font></div>
<div><font face="Arial" size="3"></font> </div>
<div><font face="Arial" size="3">Make sense?</font></div>
<div><font face="Arial" size="3"></font> </div>
<div><font face="Arial" size="3">I hope this helps you.</font></div>
<div><font face="Arial" size="3"></font> </div>
<div><font face="Arial" size="3">Terry Farrell</font></div>
<blockquote style="border-left: 2px solid rgb(0, 0, 0); padding-right: 0px; padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">----- Original Message ----- </div>
<div style="background: rgb(228, 228, 228) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>From:</b>
<a title="karlkaputt@hotmail.com" href="mailto:karlkaputt@hotmail.com">Gregor
_</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>To:</b> <a title="pianotech@ptg.org" href="mailto:pianotech@ptg.org">Pianotech List</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Sent:</b> Saturday, May 10, 2008 5:05
AM</div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Subject:</b> RE: Epoxy Bass Bridge
Repair</div>
<div><br></div>Sorry, but I still don´t understand that statement. A thin
layer of Epoxy to remain in the joint? Of which joint you are talking about:
the joint of Epoxy and wood?<br><br>What does it mean for practice? Should I
first apply a little bit of Epoxy to the wood, let it become hard, and then
apply the Epoxy with the filler?<br><br>Gregor<br><br>
<blockquote>
<hr>
From: mfarrel2@tampabay.rr.com<br>To: pianotech@ptg.org<br>Subject: Re:
Epoxy Bass Bridge Repair<br>Date: Fri, 9 May 2008 15:57:38 -0400<br><br>
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<div><font face="Arial" size="3">Some adhesives like Titebond are not very good
at filling gaps. They perform best with a tight-fitting joint and minimal
glue left in the joint. Epoxy and many other adhesives is gap filling and
you want at least a thin layer of epoxy to remain in the joint - doesn't
have to be much, but you don't want a perfect fitting joint and then apply
high clamping pressure. With epoxy you want a loose fitting joint (or
roughened up surfaces) and minimal clamping pressure - clamp pressure is not
to "clamp" as such, but rather simply to hold pieces in place.</font></div>
<div><font face="Arial" size="3"></font> </div>
<div><font face="Arial" size="3">Terry Farrell</font></div>
<blockquote style="border-left: 2px solid rgb(0, 0, 0); padding-right: 0px; padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">-----
Original Message ----- </div>
<div style="background: rgb(228, 228, 228) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>From:</b>
<a title="karlkaputt@hotmail.com" href="mailto:karlkaputt@hotmail.com">Gregor _</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>To:</b>
<a title="pianotech@ptg.org" href="mailto:pianotech@ptg.org">Pianotech
List</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Sent:</b>
Friday, May 09, 2008 11:49 AM</div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Subject:</b>
RE: Epoxy Bass Bridge Repair</div>
<div><br></div><font size="2"><font face="Arial" size="3">Terry,<br><br>what do
you mean by "</font></font><font size="2"><font face="Arial" size="3">you need
to leave some epoxy in the <font face="Arial" size="3">gap. You don’t want to
epoxy-starve the joint."?<br><br>I found a source for Western System Epoxy
handy repair set including that filler here in Germany. Good to know, I
will try it perhaps one day, but not with that Kawai. I told the customer
to ask a collegue who has 7 pianotechs working for his shop: 4 on master
level, 2 with certificate of apprenticeship and one apprentice, and they
have a huge workshop. I don´t do repairs with woodwork anymore, just
tuning, small repairs and selling pianos. But in this case it probably
would have been easier to order a new brigde from Kawai which fits
perfectly without any adjusting: just installing and it
fits.<br><br>Gregor<br></font></font></font><br>
<blockquote>
<hr>
From: mfarrel2@tampabay.rr.com<br>To: pianotech@ptg.org<br>Subject: Re:
Epoxy Bass Bridge Repair<br>Date: Fri, 9 May 2008 08:57:04 -0400<br><br>
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<div><font size="2"><font face="Arial" size="3">Epoxy repairs for a situation
as you describe can yield very good results. </font><font face="Arial" size="3">Sometimes the crack opens up a fair bit – you’ll want
to clamp it back into </font><font face="Arial" size="3">position – not to
clamp in the traditional sense, but rather to simply position
</font><font face="Arial" size="3">the parts in their original orientation –
you need to leave some epoxy in the </font><font face="Arial" size="3">gap.
You don’t want to epoxy-starve the joint.</font><br><font face="Arial" size="3"></font> <br><font face="Arial" size="3">I use West System epoxy
resin, hardeners and fillers:</font><br><font face="Arial" size="3"><a href="http://www.westsystem.com" target="_blank">www.westsystem.com</a> My
favorite for a cracked bridge is #404 </font><font face="Arial" size="3">High-Density Filler and using the West System two-step bonding
procedure described on the West System web site. The following is from
the West System web site:</font><br><font face="Arial" size="3"></font> <br>404 High-Density Filler<br>404 High-Density
filler is a thickening additive developed for maximum<br>physical
properties in hardware bonding where high-cyclic loads
are<br>anticipated. It can also be used for filleting and gap filling
where maximum<br>strength is necessary. Color:
off-white.<br> <br><font face="Arial" size="3">You can either push the
bridge pins into the uncured epoxy, tidy up and be done with it,
or, for a neater, more exacting job, you can epoxy the gap and then
drill bridge pin holes after the epoxy hardens. I have found that if
cosmetic considerations are not paramount, I apply the epoxy, clamp
together until the wood is close to original dimension, clean off epoxy
squeeze out (acetone) - at that point you will be able to see the
outline of the original pin holes - push pins in place - the wood will
have been drawn together enough to hold the pin in its original position
- and then level off and clean up the little bit of epoxy that squeezes
out of the holes as you push the pin in place. Wait a day or two for the
epoxy to completely cure, go back and install bass
strings.</font><br><font face="Arial" size="3"></font> <br><font face="Arial" size="3">I've done this repair numerous times with great
success.</font><br><font face="Arial" size="3"></font> <br><font face="Arial" size="3">And of course, on a nicer piano where the budget
allows, new bridge and/or new cap is preferred.</font><br><font face="Arial" size="3"></font> <br><font face="Arial" size="3">Terry
Farrell</font><br></font></div>
<blockquote style="border-left: 2px solid rgb(0, 0, 0); padding-right: 0px; padding-left: 5px; margin-left: 5px; margin-right: 0px;">
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;">-----
Original Message ----- </div>
<div style="background: rgb(228, 228, 228) none repeat scroll 0% 50%; -moz-background-clip: -moz-initial; -moz-background-origin: -moz-initial; -moz-background-inline-policy: -moz-initial; font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>From:</b>
<a title="karlkaputt@hotmail.com" href="mailto:karlkaputt@hotmail.com">Gregor _</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>To:</b>
<a title="pianotech@ptg.org" href="mailto:pianotech@ptg.org">pianotech@ptg.org</a> </div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Sent:</b>
Friday, May 09, 2008 5:13 AM</div>
<div style="font-family: arial; font-style: normal; font-variant: normal; font-weight: normal; font-size: 10pt; line-height: normal; font-size-adjust: none; font-stretch: normal;"><b>Subject:</b>
Epoxy Bass Bridge Repair</div>
<div><br></div>I crawled the archieves but I did not really find what
I was looking for: does Epoxy work even for bigger gaps?<br><br>I
wanted to tune a Kawai CE-11 upright yesterday but the bass bridge
looked horrible: a long gap which affected 9 notes. The gap started at
the upper pin row and the pins were vertical. Some strings rattled at
the pins. The gap expanded up to 4 mm above the upper pin row. I did
not try but I could imagine that I could have pulled out some pins
without using pliers.<br><br>First at all: I never worked with Epoxy.
My first thought was to pull out the pins, fill the gap with epoxy and
drill new holes for new pins. Could that work or is such a gap too
much for Epoxy? The bridge is made of one piece of wood, no
cap.<br><br>I was shocked about such a gap in a Kawai from 1992 (no
grey market import): no floor heating, no air con and no heater near
by the piano. And I don´t live in an area with huge differences in the
climate. Very strange. That damage is a pitty because everything else
in this piano was in a pretty good condition. But making a new bridge
would be definitely too expensive including transports from the second
floor into a workshop and back to the
customer.<br><br>Gregor</blockquote></blockquote></blockquote></blockquote></blockquote>
</blockquote><br /><hr />Connect to the next generation of MSN Messenger <a href='http://imagine-msn.com/messenger/launch80/default.aspx?locale=en-us&source=wlmailtagline' target='_new'>Get it now! </a></body>
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