In response to Dave Krall's query regarding rescaling pianos,
I additionally mentioned the recently developed method of "epoxy
recrowning" old soundboards.  I have heard the results and they
are quite impressive, especially in the bass where I have heard
a 48" upright sounding like a 7' grand!  Several variations on this
procedure have been mentioned to me, but the most compelling is this:

1) Dry the whole piano down in a low humidity space (20% Relative
Humidity or less) for at least a couple of weeks.

2) Glue the edges of the soundboard to the case (fill the crack
with glue) so it won't pop out.

3) Glue any ribs that are loose back to the board, and put
"dowels" through them and the board made of bamboo shish-kebab
skewers.  (The skewers come in several small diameters, so are
minimally cosmetically disruptive, and can be glued in place after
whatever sheet metal screws or piano wire clamps are used to hold
the board and bridges together during gluing.)

4) "Jack up" the soundboard from behind, by driving (felted) wedges
between the ribs and posts, until you just start to hear cracking.
(It doesn't take much to make a soundboard make this noise: as the
slightest fracturing of wood or a glue joint will cause it, long before
any significant damage happens.)  I have even seen a plank screwed
across the back of a piano, with threaded inserts in it, so that bolts
can be turned down to press against cauls that are placed along ribs
along the line of the bridge on the other side, to maximally press the
board out along the bridge line!

5) Fill any large cracks in the soundboard with shims made of _old_
soundboard material!  Old spruce is much harder than new spruce; new
spruce will "smush" once the board is strung and in use, defeating
some of the intended recrowning process.

6) After scraping and sanding the board, paint on the "penetrating
epoxy" of your choice ("Rot Doctor", "West's", etc.).  It can also be
used on bridges to fill minor splits, in a separate operation.  Decide
for yourself if pulling the bridge pins and sanding the bridge tops
down to the bottom of the string grooves, and then re-notching the
bridges, is worth it.  Or if a bridge recapping is called for.

7) Let the penetrating epoxy cure very well (at least a week), then
pull out the wedges, and relieve the pressure of the bolts upon the
soundboard, along the bridge line, if you've used them.

Gordon Lee Stelter
Athens, Georgia

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 [ -- Robbie