I have a 30 ounce graphite sleeve which I had used to melt bismuth in
my electric melter. What is a good way to make sure I have no trace
left of the metal before I start reusing the sleeve for silver?
Andrew Jonathan Fine
Make sure you have a very difficult, one-of-a-kind silver casting
and all the extra bismuth will surely destroy your silver casting.
Personally, I’d just get another sleeve and use the one you have for
stuff that doesn’t matter.
One way would be to flux it well and heat until the flux is melted.
Let it cool and leave it in a damp atmosphere for a while and then
remove all of the flux. The idea of leaving in a damp atmosphere is
to devitrify the flux glass and make it easier to remove without
damaging the carbon sleeve. Another way would be to skim the sleeve
in a lathe.