Growing metal brackets

[D.L. Bullock]

I have not seen the growing metal bracket, but it sounds a lot like it is
made of pot metal.  This is a metal that is heated up with a wide variety of
alloys being used.  It is poured into the mold and milled into whatever it
is to become.  Certain recipes after a certain number of years began to
explode from the inside out in very slow motion.  This can be found in
several player piano player systems.  Baldwin Manualo and Ampico player
systems both had spoolbox transmissions that were pot metal and must be
replaced with new brass ones.  The Ampico on, pedal on, repeat on, and
subdued on switches on Ampicos are always made of pot metal so they always
have to be replaced with new ones milled of brass or nylon.

I have seen some pot metal that had the right recipe and it did not change
yet after 80 or more years.

D.L. Bullock
www.thepianoworld.com
St. Louis