Another Separated Back

[Terry Beckingham]

Hi All,

I have been following the thread about the separated back with some
interest. I am working on an old Willis upright which has (or had) a similar
problem. 

I removed the plate to repair the soundboard. It wasn't until after the
soundboard repair that I noticed that the piano back was bowed out
approximately 1/8 inch in the centre. That is, it was bowed out to the rear
of the piano. Laying a straight edge across the front of the pin block
confirmed this. 

I stood the piano up and placed a beam across the back and clamped it at the
sides with a wedge in the centre, just to see if I could force the back
forward into place. There was some evidence that the back posts near the
center had separated slightly from the pin block. The back is solid.
Regardless of how much pressure I applied to the clamps, the back would not
move. In fact, I only succeeded in bending the 4 x 6 beam. I therefore
filled the gap between the backposts and block with glue and let it set.

When I went to re-install the plate, I noticed that it was slightly convex.
When I laid it in place on the piano, the space between the pin block and
the plate was nearly 1/4 inch. 

I assumed that this piano must have been in this state when I disassembled
it and bolted down the plate. The plate and the pin block came together
nicely. I didn't realize that there would be that much flex in the plate.

My question is: what will happen when I restring and bring the piano back up
to pitch? I am assuming that since it was in this state before, that I will
be able to bring it up to pitch without any problem.

Does anyone have any comments or suggestions? I am relatively new at this.
This is only the third piano on which I have attempted major repairs.

Terry Beckingham
PTG Associate Member