Oxidation using glass high temperature enamel on bronze

Jewelry Discussion
1

Hi all, I have been asked to make samples of 95/5 bronze medals using
transparent red glass enamel. The corners and some edges show black
oxidation underneath the red. Is there any way to avoid? I am using
German enamel and firing at 875 C which is about 1600 F in a tiny 4
inch X 3 inch X 5 inch electric furnace. I tried with some argon gas,
the result is better but inconsistent. Using a larger furnace of
about 6inch X 6inch X 10 inch depth worsened the result considerably.

Thanks and regards
Shishir Nevatia

2

Shishir Bhai, Try firing it in a Dental ceramic furnace, where the
firing is done under vaccum , experiment and find out if it helps.
best of luck.

Best regards
Umesh