Jay Whaley will most likely reply to you, but is teaching a class at
the moment.
I see him and his students cast S88 925 silver many times in the
week, none of what you describe is familiar to me. I have seen zero
failures, even from first time students.
We burn out over an 8 hour time span starting to wax melting at 500
farenheit, and then ramping up to 1200 to 1350, holding there for
some time, and then ramping down.
As soon as the flasks are out of the kiln for maybe 5 minutes, they
are doused, and the investment is shed. The castings are solid,
without porosity, and as smooth as the waxes they were cast from.
Any short cuts are not worth it.
I will ask Jay to respond, probably mid day tomorrow.
We burn out over an 8 hour time span starting to wax melting at
500 farenheit, and then ramping up to 1200 to 1350, holding there
for some time, and then ramping down
If I were you, I would call the tech people at United Precious
Metals in NY. They have all kinds of specialty silver and gold alloys
for almost all applications. The S88 sterling I have been fabricating
and casting with for a few years now is just about trouble-free, and
I would highly recommend it.