Upper back repair

[Jon Page]

Warren,
Look for about 1/4 tone pitch raise. Tune it later.
Depending on the type of wood on the back you may need to put
washers to reduce compression. Suspect the bottom as well,
tip it back and replace all screws with carraige or machine bolts,
even if they are not loose or the back separated. Support and replace
the treble plate screw behind the bridge, also. Because if they are not
loose now, they will be. All these things should be carraige bolts anyways.
After all these years of piano construction you'd think they'd build 'em
like brick shipyards, and not rely on glue so much.
Definety clamp surfaces closed before drilling to insure hole alignment.
3/8" bolts is sufficient.
Jon Page
Harwich Port, Cape Cod, Mass. (jpage@capecod.net)
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At 05:27 PM 3/6/97 -0800, you wrote:
>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
>
>

Jon Page
Harwich Port, Cape Cod, Mass. (jpage@capecod.net)
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