hey,
Just what are you trying to make Zippy? Are these objects jewelry
size or basketball size? Casting copper is not for a beginners. It
melts HOT, almost 2000F. It flows poorly into molds, and is subject to
oxidation, which will make porous, crappy looking castings. I think
unless you are an experienced caster you are setting yourself up for a
LOT of frustration. Maybe fabricating is a better idea. Even in the
early days of metalworking, copper was rarely cast into a finished
shape, for the same reasons mentioned above and by others. Ingots of
copper were cast and then the metal was beaten, sheared, sawn, stamped
or otherwise shaped (either hot or cold) into finished products. Makes
sense I think. Basic hand tools are cheap compared to casting equipment
& supplies. Then again you could probably look for a commercial caster
who might be willing to cast your molds. I suspect most will avoid it
like a plague or charge trough the nose.

Glen G.