Supplamental technique study for fine tuning unisons (long) The odd thing is...

[Joe & Penny Goss]

Hi Dan,
In working the wire you are ( if it is already seated on the bridge and
other bearing points ) you are slightly unleveling the string and changing
the curviture at the termination points. The elasticity of the wire will
soon return the string to its former shape raising the pitch.
Your tool sounds like one that I have and use a lot.
http://www.primenet.com/~imatunr/
Joe Goss
From: Dan & Martha Reed <thepianoarts@home.com>
To: <pianotech@ptg.org>
Sent: Thursday, July 27, 2000 9:10 PM
Subject: Supplamental technique study for fine tuning unisons (long) The odd
thing is...


> List,
>
>      For a few years, I have been actively experminting with trying to
> accuratly set unisons with techniques in addition to hammer technique. The
> reasons I have searched for additional methods, have to do with the
> limitations of my hammer technique, to be sure...but, never the less, some
> pianos resist fine unison setting. Some fellow technicians (famous
people!)
> are also experminting and using string stretching tools to change the
pitch
> a little.
>      The reasons some pianos are difficult in this area of fine unison
> setting are numerous and vaired, and should be studied in order to better
> understand the cure.  But please allow me to move on to the strange
reaction
> I am getting from one technique.
>
> The problem:
>
> A three string unison (solid wire) which is not clean...
>
>    In setting the three string (solid wire) unison, for purposes of this
> example, mute the left wire, so as to hear only the middle and right wire.
> Again, for this example, we determin that the right wire is slightly
sharp.
>
> The technique:
>
>     Using a 1/8 th.inch diameter brass dowell, with a modestly tapered
end,
> with a rounded (smooth) grove cut into it, I 'rub' the wire like I am
trying
> to polish it. Five of six strokes will lower the pitch. In the middle of
the
> piano, a unison which is one or two beats high, can be coaxed down with
this
> technique, usually in one (six stroke) pass.
>     On some wire, one can feel 'bumps', where the wire is either slightly
> bent, or just unevenly drawn. I think to myself that I am 'strightening
out
> the wire' with this technique, because the pitch comes down. ( I try and
> avoid pushing down on the wire, so as not to introduce excessive
distortion)
>
> One other wire, there is quite a bit of resistance from corrosion.
>
> The odd thing is, that the pitch comes right back up. Just strike the
note,
> and hear it start to go sharp again. After four or five hard blows, it is
> back to (about) where it started before massaging. (I am an aural tuner,
and
> I check the individual wires with thirds or sixths. It is the massaged
wire
> that is comming back up, and not the other wire going south.)
>
> Just when I thought I had found a nice accurate controlable method to
subtly
> change the pitch to clean up a unison!
>
> Dan Reed
> Dallas Chapter
>
>