Lyre Braces

[Farrell]

Epoxy-ing metal to wood can be done in excellent fashion. I have done this many times in marine and aquarium applications (and some piano). I use West System resin with their (from the West System web site - http://www.westsystem.com/ ):

404 High-Density Adhesive Filler
404 High-Density filler is a thickening additive developed for maximum physical properties in hardware bonding where high-cyclic loads are anticipated. It can also be used for filleting and gap filling where maximum strength is necessary. Color: off-white.

They have a nice guidance document that describes how to bond metal to wood. What I do is sand or grind to bright metal, coat with epoxy then sand fresh unthickened epoxy into surface of metal. Re-coat or bond after first coat gels. Coat the wood also when you do the metal with unthickened epoxy. Then mix up some #404 into the resin until it is like peanut-butter. Squish in the thick stuff put it all together, wait a day, and you have one thing that used to be two.

Please write back with any questions. This is a great way to absolutely make a solid unit.

Terry Farrell
  
----- Original Message ----- 
From: "Jon Ralinovsky" <ralinoj@muohio.edu>
To: <pianotech@ptg.org>
Sent: Tuesday, April 23, 2002 6:39 PM
Subject: Re: Lyre Braces


Avery,
Is there a reason that epoxy wouldn't work to set the brass sleeve in 
place in the lyre brace?  Joel's solution sounds as if it works well; 
I'm just looking into alternatives.

Respectfully,
Jon

>
>I sent this to Joel Rappaport and below are his comments about it (with
>his permission):
>
>>  As far as the comments from Michelle L Stranges on the current Baldwin
>>system, if it is the same system that we experienced for the last four
>>summers at Tanglewood, all I can say is "no, no, No NO" IMHO.  Those little
>>T-screws go into a brass sleeve that is knurled and inserted into a hole
>>drilled into the top of the wooden support stick.  Problem is, the sleeve
>>goes into end grain and even though knurled, has a tendency to become loose
>>so that not only is the stick no longer adjustable, you can't shorten it
>>enough to remove it.  So the whole lyre now has to come off to repair the
>>exquisitely engineered feature.  The factory 'solution' is to drop CA glue
>>around the sleeve to 'fix' it in the wood.  We tried that at Tanglewood and
>>the result was that the sleeve then twirled around in the CA glue instead of
>>the wood.  We had to (with great trouble) remove the sleeve and glue veneer
>>into the hole to provide some flat grain, then reinsert the sleeve.  That
>>was the only thing that worked.  This was probably the one most common
>>complaint we had to trouble shoot, even more than tuning calls.
>>Ted Sambell's and Denis Brassard's invention sounds so much better.  And I
>>have seen the threaded brass cup on Bösendorfer grands, too.  It's a nice,
>>simple and _workable_ solution.

Jon Ralinovsky
Piano Technician
Department of Music
Miami University
513/529-6548