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Harold & Susan Vordos
 
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Default Kilns and Furanaces


"Zipper" wrote in message
et...
I was wondering if I could get any advice on Kilns and Furnaces. I would
like to start doing some casting of Copper, but I'm afraid I don't know

much
about kilns and furnaces. I've been reading stuff online and I also bought
"The Complete Metalsmith" by Tim McCreight, but he doesn't really say what
to look for in a Kiln. I was hoping someone could point me towards either

a
FAQ or good book about this. I'm looking to buy used, but I do need it to

be
in good condition as I would not know how to repair it. I'm trying not to
spend more than $1,000 (USD) for the kiln. Also if someone could help me

on
where to get a ceramic crucible, I'll be dealing with 99% pure copper so

I'm
trying not to get something that would be more likely to introduce
contaminates in to the copper. Sorry for asking so many questions

recently,
but I don't have anyone around Atlanta that can teach me about

metalworking.
Thanks

-Zipper

Depending on the volume of copper you'd like to cast, I don't think you
really want a kiln. Non-ferrous metals are typically melted and cast from
small furnaces that are natural gas, propane, or oil fired. They are known
as crucible furnaces, and the crucible of choice for melting the metals
would be made of either graphite/clay or silicon carbide. That's not to
say that a kiln can't and won't do the job, but they aren't really made for
the type of access one needs to remove a crucible of molten metal as easily
as a melting furnace is.

These crucibles (bilge type) are available in a myriad of sizes, and are
named by the amount of aluminum they can melt. With that in mind, you
triple the number appropriate for aluminum and that gives the approximate
amount of copper or copper alloy one can melt. A #8 crucible, for example,
would be capable of melting about 24 pounds of copper alloy.

There's a company that makes small melting furnaces (McEnglevan), which have
been used extensively in high school and other programs. With the closing
down of the industrial arts programs in our school systems, it's common for
school districts to auction off these furnaces, along with related foundry
items. If you keep your eyes open, you may hear of such an auction near
you. It's happening across the nation, thanks to the "wisdom" of our
learning institutions, who seem to think that guys (and gals) have no need
to learn how to work with their hands, especially now that we're officially
a service society. (Yeah, I know, that sucks!)

If you're handy, you can actually build your own furnace, something that I,
and many others on RCM, have done, with great success. My designs were
based on the McEnglevan models, which work exceedingly well. One need not
stick to any particular design, though it makes sense to not re-invent the
wheel. I might suggest that you explore this matter further before making
some decisions that may not be in your best interest.

Good luck!

Harold