[pianotech] UK Glue for loose bridge pins

[Douglas Gregg]

This is a situation that requires a filled epoxy to prevent
compression creep. Most pure epoxies under constant pressure will
slowly give and "flagpole" since they are really just a form of
plastic. Use a steel filled epoxy and it will withstand much more
compression. I like either JB Weld or Marine Tex Black or any other
epoxy steel formulation. I am not sure what is available in the UK,
but I would first try an auto supply store for an epoxy filled with
steel filings. The package will say that it is machinable. I recently
filled a couple of tuning pin holes with adjoining large cracks with
JB Weld. I could just pick the tuning pins out by hand, the holes were
that large.  I heavily coated the pinblock hole and put the tuning pin
into the JB Weld coated holes. The pins were first coated with a good
coat of paste wax so they would not stick to the epoxy and would
later move. I trimmed off the excess that squeezed out  with a sharp
chisel when it was half set. It worked like a charm. Be sure to give
it the full 24 hours to cure before putting force on any of these kind
of repairs.  The temptation is to just wait until it is hard to the
touch but it is not hard enough to take the compression force until it
is fully cured.

Doug Gregg
Classic Piano Doc
Southold, NY 11971