Just thought I’d add my 2 cents here too;O) What we have been
taught at Cape Technikon, Cape Town, RSA when smelting metal is this:
1. Choose ingot 2. Pour in a little car oil 3. Heat up ingot 'til no more oil left 4. Now heat up metal in crucible, whilst holding over heated ingot (if 1 of the flat ingots...) 5. Add borax once molten and pour into heated ingot. 6. Remove bar ASAP and quench.
We are only working in silver at present, but I’m sure that most of
the above goes with the smelting of other metals. Doesn’t it?