sagging center string

[Brian Trout]

Hi Ed,
Does the string go flat regardless of whether you tune the left string or
the right string first?  (If you tuned the left string first, then went to
the middle string to tune it, would the left string be flat till you were
done tuning the middle string?)

If the piano is not close to pitch, if it did have a positive downbearing, I
would suspect that with each string you pull up to pitch as you proceed up
towards the top, you would be putting more downward force on the soundboard
thus slightly 'loosening' the strings you've just tuned, and actually the
ones you haven't tuned yet as well.  I may be off base here, but it's the
mental picture that comes to my mind.  (That's if the basic framework of the
piano is solid.)

A second place I would be thinking about is the integrity of the framework
and the pinblock.  Is the pinblock still in place and glued to the back as
it should be?  If it's coming loose, that can be a major problem with tuning
instability, and I would wonder if it could cause a broken plate in an
extreme case.

A third thing that comes to mind is whether or not the screws that hold the
plate to the rest of the piano (including the pinblock) are loose.  If they
are loose, I would think that could cause some tuning instability as well.

Another thing I would wonder about is how well the tuning pin is set when
you move on to the next string.  It took me years to get the hang of setting
a pin, and there are still some pianos that can be difficult.

Just a few thoughts.  Perhaps there'll be more ideas.

Good luck,

Brian Trout
Quarryville, Pa.

-----Original Message-----
From: Ed Carwithen <musicman@eoni.com>
To: pianotech@ptg.org <pianotech@ptg.org>
Date: Sunday, June 13, 1999 8:58 PM
Subject: sagging center string


>Most of my clients have older (much older) pianos (mostly uprights).  I
>don't have much trouble with the lower or middle section, but that treble
>section often is a real pain.  I use an SAT (God Bless Mr. Sanderson), so I
>am able to get immediate feedback when the pitch slips, and after tuning
>the center string, I go for the treble (right) string, and when it comes in
>tune, the center has slipped, sometimes a lot.  By the time the left string
>is being worked on the center may be even flatter than when I started.
>
>I start compensating by leaving the center string higher and higher with
>each set, and sometimes this helps, but chasing the pitch of the center
>string down the musical scale is a real pain.
>
>Eventually, I get the strings to go where I want, they even stay in tune
>pretty well, but the time involved is frustrating.  There are times when it
>takes me more time to tune from F4 to C7 than the entire rest of the piano.
>
>
>Does anyone have any suggestions as to how I might improve my technique in
>this area of the piano.
>
>P.S.  I already do a quick pitch raise if the piano is 6 cents or more away
>from 440; I will even to do the treble section quickly a second or third
>time if it drifts flat.
>
>
>Ed Carwithen
>John Day, OR
>
>