I have been using my Burno crucible for melting sterling silver, and
notice that the borax which used to completely coat the inside of the
crucible is all pooled up on the bottom of the crucible.
Is it necessary to recoat the crucible, so that the section that
holds the metal is completely coated with borax?. If so, should I
remove the old glassy borax at the bottom of the crucible? If so, how
should I remove it? The old borax is sort of brownish red, caused I
believe by the cuperous oxides in the sterling.
I read somewhere that one could coat the cruicible by filling it 1/3
full of borax, and putting it in the kiln to heat, rotating it around
so that the molten borax completely covers the sides of the crucible.
If this is the proper proceedure, what temperature should I heat my
kiln.?.
Even with heavy leather gloves and tongs, this seems like a
difficult proceedure. Is there a better way than using the kiln?
I will appreciate advice on the proper care of my crucibles so as to
insure longevity.
Thanks Alma