[pianotech] Plate Location

[Jon Page]

Here's my block duplication procedure:

Once the piano is unstrung, drill two indexing holes at the treble and
two at the bass ends thru the plate and into the block, 5/16" bit.
Remove plate.

Make a template of the index holes in the block by trimming two pieces
of paper to fit the case corners. Place the edge of the paper against
the side or front, hold a straightedge against the opposing side and
trim the paper with a razor blade. This will duplicate the angle. Fit into
the corner, punch the holes with a pencil.

Fit new block to the flange, clamp in place and install all screws. Remove
block, apply epoxy paste to flange and reinstall with a sufficient amount
of screws.

The plate is now in its fitted position. Drill indexing holes into new block.
Center punch tuning pin holes. Once epoxy cures, remove block.

Place templates on new block and index the holes. Trace the template
corners onto the block, connect the front lines with a long straightedge.

Trim the block on a bandsaw and fit to case. Bevel the bass and treble
ends to allow the block to be angled in.  Since the bass edge has a small
footprint, slightly bevel top portion and the bottom portion on the treble.
Fine fit the front edge with a jointer and hand-held belt sander on 
the two ends.

The block can be fitted with zero tolerance. Verify with corner templates.
The plate will go back in the same location.

Before gluing in, drill pin holes on a drill press if so inclined. I also glue
the block in place with it screwed to the plate to allow for any minor
curvature of the plate.

If you're going to refinish the plate, during the epoxying procedure;
after drilling the indexing holes, plug the holes with excess epoxy.
I use an epoxy paste called MarineTex, very high compression strength.
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Regards,

Jon Page