need ideas (more)

[jolly roger]

At 10:52 PM 4/9/01 -0700, you wrote:
>At 10:54 PM 04/09/2001 -0500, Keith wrote:
>>I'm going to take three pieces of hard rock maple 1' x 4" x 57 1/4", locate
>>them evenly spaced from top to bottom and join the five back posts
>>together.  I feel confident this will make a remarkable change in the
>>stability.
>>
>>Still open to any other constructive ideas that someone might have, or ones
>>that someone has possibly implemented and had success.

Hi Kieth,
               A calculated guess of what is going on, is trapezium
distortion of the back assembly.
Remember to clamp and glue the 1 X 4" slats and use two screws per post.
Two slats should be more than enough if this is the cause of the problem.

Really check the plate bolts. If my memory is correct, you will have to tip
the piano and remove the trap board to get at the lower bolts.  Also
carefully check the lower spacer blocks, if one of them has a failed glue
joint, this could cause the problem.  As the back post shrinks, the spacer
block end grain glue joint some times fails. ( not the strogest type of
joint)  Seal the gap with water thin West system epoxy, ( remember to tape
the bottom of the post and block, with trap board off) also toe a 1/2"
maple dowel through the block and into the post. (It's easier from the
bottom). I believe these blocks use to be morticed??????

You coud dry fit the slats with screws and C clamps to test the theory.

Just some late night ramblings.
Regards Roger