Disappearing diamonds fired in PMC

Jewelry Discussion
41

The organic binder in the PMC is igniting the diamonds. which will
not burn casting pure silver with proper procedures in lost wax. PMC
requires an oxidizing atmosphere to work.

jesse

42 
The organic binder in the PMC is igniting the diamonds. which will
not burn casting pure silver with proper procedures in lost wax.
PMC requires an oxidizing atmosphere to work.

This is not quite correct. The organic binders in metal clay burn off
at about 800F. I believe the damage to the diamonds happens at a much
higher temperature than that. Also, PMC does not require an oxidizing
atmosphere to sinter properly. In fact, several types of metal clay
are available in Japan, but not sold in the US because they require
reduction atmospheres to work (e.g., green and red gold clays) and
the equipment for this is too expensive.

I believe the real key to why soldering and casting with diamonds in
place does not cause a problem is because the time at temperature is
much shorter than is typical of metal clay sintering.

Mary Ellin D’Agostino, PhD
www.medacreations.com