Roger Hull wrote:
I have zero foundry experience. I want to melt a few pounds of Copper and
cast it into backup plates for welding. What should I make the crucible and
moulds out of? OR, is it possible to buy a crucible somewhere?
Thanks.

Roger in Vegas
Worlds Greatest Impulse Buyer


You'll need a silicon carbide crucible and a furnace capable of about
2100deg. I've melted copper scrap using a propane furnace. It takes a
long heating time and leaves a lot of dross or oxide. The pieces of
scrap (in my case, copper tubing) seem to hold their shape due to the
outer layer of oxide. The copper inside melts away leaving the vague
shape of the original piece until well along in the heating process.
Finally, the oxide crumbles and floats on top of the molten copper. It
then has to be skimmed and the high heat of the copper tends to make my
skimmer less than sturdy. It can be done, but melting aluminum is a
better experience.

Gary Brady
Austin, TX