Bridgemeister

Larry Fisher larryf@pacifier.com
Sat, 11 Nov 1995 17:26:27 -0800 (PST)


With regards to the replacement of bass bridges, I've always used Titebond or
Elmer's Wood Glue, and have always loaded the strings on the bridge as soon as
I'm done reattaching the bridge to the soundboard or apron.  The thickness of
the glue at the glue joint is so thin by the time the screws are tightened, that
the vibration amplitude of the bass frequencies should overcome any flexible
consistency in my choice of glue.  The downbearing of the strings helps put
pressure on the glue joint that is being held fast by the properly fitting wood
screws anyway.  The finished product usually generates such a satifying
improvement over what was there before hand with a the bad bridge, that the
small potential loss of sound by using something less ridgid than hide glue is
imperceptable.
     On the subject of attaching the bridge to the apron by drilling holes from
the bearing surface down to the apron, then plugging the holes and hiding the
screw heads for the next 75 years, I shutter a bit.  While I do agree, this
method really attaches the bridge quite nicely to the apron, and who's to say
this piano will ever need another bridge, .......who's to say this piano won't
be around for another round of bridge work??
     That brings us to re-attaching the bridge by removing the apron from the
soundboard, putting the screws through from the blind side, the way the factory
did it in the first place, and then re-attaching the bridge to the soundboard.
First off, removing the apron from the soundboard can be a real challenge since
they are usually installed before the plate is lowered on to the case.  Leaving
the problem of the plate being an obsticle, aside for now, I'd like to focus on
the actual removal of the apron from the soundboard.  On vertical pianos, there
almost always is a backpost in the way of at least one screw passing through
the soundboard to the apron.  I've always simply drilled a half inch hole as in
line with the screw head as I could aim, right through the backpost.  I'm open
for flames on this proceedure.  Next, if the glue joint was old enough, usually
the apron simply separated from the soundboard with very little effort once the
screws were removed.  For those glue joints that were still doing their job, I
have used a funny looking chisel available from the supply houses, to disturb
the glue joint all along the edge of the "stick".....the piece betwixt the
soundboard and the apron.  Usually the apron is failing and in pieces and so it
falls off.  I've had a few where I've had to literally rip the apron off the
soundboard.  This usually takes a little of the wood of the soundboard with the
stick.  As long as I glue this same piece back into the same place it came out
of, I've never had any problem.  I can't see me doing this on a fine grand
however, and would like to hear some comments/flames on a better proceedure on
getting the apron to separate from the soundboard.  I write this openly and
with no regard for my personal appearance to you, with hopes of learning how to
better my trade and the benifit of others to learn.



--- Larry Fisher RPT, Portland Metro's Authority on PianoDisc Systems
        For more information call (360) 256-2999 in Vancouver, Wa.
                      or email larryf@pacifier.com




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