On Thu, 22 Jun 1995, Ron Torrella wrote:
> Subject: Squaring Agraffes
> On P. 16 of the May '95 _Journal_, Steve Brady answers a question for Zen
> Reinhardt who asked about straightening out askew agraffes. Steve's
> answer made me think a little about that procedure because he didn't
> mention anything about removing strings before trying that operation.
> Seems to me that the topmost portion of the agraffe is the most vulnerable
> part--too much torque and you can shear it right off. I've never
> deigned to straighten an agraffe that had strings running through it
> because, as straightening them is part of my restringing (or occasionally
> repairing) protocol, I always thought it was safer to get whatever tool
> you happen to be using to tighten the agraffe as close to the ledge of the
> agraffe as possible (see below).
> _
> | |
> | |<----- String holes
> Ledge---> _| |_
> --------|_____|-------- <----Plate
> | |
> Threads---> | |
> |___|
>
> Am I being over-cautious or is tightening an agraffe with contact in only
> the top half (ie. above the string holes) of the agraffe hazardous
> business?
________________________________________________________________
MY REPLY
If you try to force an agraffe which obviously doesn't want to
move, it's hazardous business no matter where you apply the force, but
probably even more hazardous if you apply the force above the holes. As I
pointed out in the answer you referred to, you don't want to force the
agraffes. You've probably seen old Steinways where the agraffes had been
twisted in after they had stopped turning in the hole; the installer
actually forced a plastic deformation into the top part of the agraffe.
These are often the ones we have to replace when they break 60 years later.
In newer pianos, I do frequently square agraffes to the strings with
the strings in the piano and at full tension. Most of the agraffes seem to move pretty
easily. If they resist much, I just leave them where they are. Some are
so loose they don't stay squared after you square them. This is no good,
and often results in buzzing noises.
The right way to correct that is to use thin washers under the head of the
agraffe or to remove material from the bottom of the head with an end
mill. This is also the correct procedure for agraffes which can't be
squared without forcing them beyond the elastic limit. Needless to say,
you have to remove strings (and the agraffes) to do that kind of work.
Steve Brady, RPT "The most expert and rapid tuners are...
University of Washington possessed of a highly excitable,
sbrady@u.washington.edu nervous, and emotional temperament,
verging on the border of insanity at times."
-Daniel Spillane, The Tuner's Guide
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