[CAUT] Sostenuto Trap Lever Repair

mcneiltom at aol.com mcneiltom at aol.com
Wed Aug 11 06:42:14 MDT 2010


Hi, Paul - 

A glue repair should work well in this situation.  A break along the grain, not having been glued previously, will provide a perfect fit.  And the resulting joint can indeed be stronger than the original wood.  And besides, it was holding - almost anyway - with a bit of packaging tape. 
We should try to determine why this failed and see if we can prevent a recurrence.  Of course being made from cross-grain stock makes the lever weaker, but it took pretty substantial loading to cause this failure.  This appears to be the 'second' lever, the one pushing the pitman dowel.  And the stop felt is provided near the end bearing the pitman.   That arrangement is OK for the light loading ordinarily encountered, and it's easy to install there.  An improvement is to place the stop on the other lever, above the pedal rod, protecting both levers and everything 'downstream' from excess load.

Yes, that's leather on the rounded end of the lever.  (The other lever will be bare wood).  Not much trouble to replace it while the lever is on the workbench.  Peel it off, scrape to bare wood, and glue the new leather on with contact cement.  Use flexible leather about the same thickness as original.  The smooth side gets the glue; the 'suede' surface will bear against the other lever. Make the new leather large on all three exposed edges and trim neatly with a razor blade after gluing.  Rub a bit of grease into the 'suede' and your done.

~ Tom McNeil ~ 
Vermont Piano Restorations

Sent from my Verizon Wireless BlackBerry

-----Original Message-----
From: "Paul Milesi, RPT" <paul at pmpiano.com>
Sender: caut-bounces at ptg.org
Date: Wed, 11 Aug 2010 02:11:11 
To: PTG CAUT List<caut at ptg.org>
Reply-To: caut at ptg.org
Subject: [CAUT] Sostenuto Trap Lever Repair

Check out the attached photos of a 1970 Steinway D sostenuto trap lever
which is cracked the long way and with the direction of stress.  Someone
tried to repair it at some point by wrapping it with packing tape (no glue).

What are the chances of effecting a successful glue repair?  I know I've
been told many times that a glue repair is stronger than the original wood,
but will it really take the stress of the leverage applied by the sostenuto
pedal along such a long break?

I just finished loading it up with Titebond and clamping tightly with an
aluminum rail on one side for support, and a couple small clamps holding
portions that extend to a point, etc.  Figure I'll give it 24 hours clamped,
see what happens.  Any bets?  If it doesn't work, I guess the school will
just have to spring for a new one.  If this piano ends up being used for
recitals, would buying new be more reliable than a repair?

Also, the half-rounded part that interfaces with the other wooden lever
seems to be covered with something thick and black.  Is this just old grease
of some kind, or is there supposed to be leather there and it's
disintegrated?
-- 
Paul Milesi, RPT
Staff Piano Technician
Howard University Department of Music
Washington, DC




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