Quick background, I built a home studio about 3 years ago after
being out of the jewelry industry for about 20 years. When I left
gold was around $300-400 an ounce. To get started I was working with
metal I had around, copper pennies (pre 1982), copper wire (from home
electrical projects) and brass plumbing fittings (I switched from
jewelry to pipefitting and plumbing). I thought," I've cast with gold
and silver, these silly non-precious metals will be simple to work
with." Hah! It's taken me these last 3 years to teach myself how to
successfully cast these ancient metals, and that's casting more than
I did during my previous 15 years as a jeweler the first time around.
Some things I have learned.
Copper isn't an alloy but a pure metal. It melts differently than an
alloy, like sterling. Since it is pure it's melting point and
liquidus temperature are the same, with an alloy they aren't. An
alloy will melt but then it needs additional heat to reach it's
liquidus temperature, when it will act like a liquid and actually
pour Copper's liquidus temperature is high, 1981* F *(*1083 C*) as
opposed to sterling silver which is *1650 F* (899 C). I use an
electromelt furnace and copper (along with cast iron, but that's
another story) pushes the upper limits of the equipment.
You cannot use a steel (or iron, ferrous metal) ingot mold. I made
my own a graphite crucible from a brick of graphite I purchased on
Ebay. It was less expensive to by the brick then an existing graphite
mold plus I still have a good sized chunk which I use for other
If you are casting with it polishing the piece is a bear, if you
look at it the wrong way it will ding the surface.
I tried casting with it and THEN read up on it. What I found
suggested it was difficult to cast on a small scale. It is but it can
be done (same with cast iron).
Hope this helps.