casting low nickel copper

I'm going to try casting some pendants and read of the problems
associated with casting pure copper. I heard of a guy who used nickel
coins (I know it's illegal to do this) for his castings. I found out
that nickel coins are 25% nickel and 75% copper. So my question is
this:
Can I cast copper at say 95% copper and 5% nickel? Will it get rid of
the surface cracking and other problems associated with casting pure
copper? Will it look copper colored with a hint of nickel color? (Thats
the effect I'm after)
If it helps to know this, I'll be using a basic sand casting technique
and a oxy-acy. torch to heat the (very small) amounts of metal for a
pendant.

wrote:
I'm going to try casting some pendants and read of the problems
associated with casting pure copper.
Can I cast copper at say 95% copper and 5% nickel? Will it get rid of
the surface cracking and other problems associated with casting pure
copper? Will it look copper colored with a hint of nickel color? (Thats
the effect I'm after)
If it helps to know this, I'll be using a basic sand casting technique
and a oxy-acy. torch to heat the (very small) amounts of metal for a
pendant.

One suggestion: avoid the metal nickel, for a many reasons, including
the fact that a lot of people get an allergic reaction to minute amounts
of nickel in jewelry worn against the skin. And the potential nickel
vapors/dust when you do the casting. Has been banned for use in jewelry
in Europe, I believe.

If you are only using small amounts of metal, consider ready-made alloys
from one of the major metal/jewelry suppliers. I have had great results
with their bronzes -- both silicon bronze (easy flowing) and an "ancient
bronze" formula. These are already in a grain for easy melting, and have
other advantages, for example, some have anti-oxidant additives. The
bronzes take some nice patinas.

If you want to use scrap copper to save money, than that's another
matter. Believe the new plumbing solders have a high tin content, with
no lead, and if this is the case, then you could experiment with using
this with scrap copper. You could also add some scrap silver, which
might offer a nice marketing angle for the pendants. (Some people want
to have some precious metal, even if they can't see it.)

There are a lot of possibilities, and you might want to look up some of
the traditional, historic alloys used in Japan for mokume, etc. There's
a whole interesting world of copper alloys out there -- without using
nickel.

Thanks for the advice, I'm glad I asked before getting stuck into a
potentially hazardous casting situation. I won't use the nickel, but I
have some silver. How little silver can I get away with adding to
copper to get over the copper casting problems? I know sterling is 92%
silver 8% copper.....can I use a 50/50 mix or even less? I want to keep
the copper color.
Thanks.

wrote:
Thanks for the advice, I'm glad I asked before getting stuck into a
potentially hazardous casting situation. I won't use the nickel, but I
have some silver. How little silver can I get away with adding to
copper to get over the copper casting problems? I know sterling is 92%
silver 8% copper.....can I use a 50/50 mix or even less? I want to keep
the copper color.
Thanks.

Alloys are something I have not explored much, and I did a quick look on
Yahoo and ended up with a lot of non-jewelry alloys. Remember I
mentioned traditional Japanese alloys? I took a quick look at the site
for Reactive Metals (recommended supplier) and found some good info on
low-silver copper alloys, and low-gold copper alloys too. The URL for
that page is http://www.reactivemetals.com/Pages/rmsbime.htm.

One of the beauties of these alloys is the subsequent patinization,
especially if you have two or more alloys in one piece of jewelry. So,
yes indeed, you can use far less than a 50/50 mix of copper and silver.
Heck, you can have a lot of fun experimenting with a whole lot of
combinations.