Formaldehyde glue

[Kenneth Zahringer]

I was recently called to check out a piano that another technician had
declared untuneable.  Well, he was right.  The pinblock had completely
separated from the back beam - end to end, top to bottom.  I looked in
the gap and both surfaces were covered with what looked like a flocking
of glue.  I scraped some of the glue from the underside of the block, in
back, and it crumbled in my fingers - full of air bubbles, I think.
Once it crumbled, though, the remaining granules were rock hard.  The
manufacturer said at the time this piano was built they were using
formaldehyde glue in this joint.  The warranty expired some years ago,
so it's up to the owner and me to fix it.  I would like to do this
without disassembling it, replacing the block, and restringing it.  It's
not that old and the pins are still fairly tight.

My problem is that old glue.  I know there is no way I could clean all,
or even most, of it out of a gap that's barely 1/4 inch wide.  And the
granule are so hard I'm sure they would prevent the two surfaces from
being clamped together effectively.  Does anyone know of a way to soften
or dissolve formaldehyde glue?  Can it be "reactivated"?  If it were
softened or partly liquefied, would it interfere chemically with other
glue, like Titebond?  Based on what little I know about formaldehyde
glue, I'm not sure I want to use it in my shop.

Ken Zahringer, RPT
Columbia, MO