Upper back repair

[Warren Fisher]

I have a yamaha school studio in a public school that has the upper ends
of the back posts and its cross board pulled away from the pin block
about a quarter inch on the left tapering to a crack on the right. My
intent is to put glue in there, put about ten pipe clamps across the top
and then remove the top plate screws and drill all the way through to
the back to install large 6 large bolts to support this puppy.

Do any of you have any thoughts, warnings, tips or reservations about
this process?

I have a couple of questions:

1. If I just tighten this back up after gluing, how much pitch increase
will I get?  The piano is just a little flat. Could it be too much?  Do
I need to release string tension with all that can of worms?

2. Is there anything else I should check before I start gluing?

Any help will be greatly appreciated?

Warren
--
Warren D. Fisher
fish@communique.net
Registered Piano Technician
Piano Technicians Guild
New Orleans Chapter 701