Summary for copper pennies as alloy Discussion
Copper pennies as alloy is the wrong approach for making silver jewelry, according to Ted Mooney. He advises using copper wire instead, noting that hardware-store wire is typically over 99% pure copper and can be cut into small pieces so it will dissolve more easily into molten silver. He also warns that modern pennies are usually zinc with only a thin copper plating, so they are not a reliable copper source. In response to Shelley’s beginner questions, the thread suggests that the main concern is choosing a clean copper addition rather than worrying about pennies contaminating the silver. The excerpt does not give a detailed answer about overheating or underheating silver, but it implies that proper melting practice matters and that using the right alloying material is the safer route.
Q. I’ve just begun simple jewelry making with grade 9 students. I have access to some tiny 999% silver bars and was hoping someone could tell me how to add an alloy to them. Can I use copper pennies? We have a forge and other equipment. Most of the equipment has been used for casting aluminum. Can this contaminate the silver when I melt it down?
Can I ruin silver by under or over heating it?
Thanks,
Shelley – a true beginner
(an old archive would help)
S Thompson
1998
A. Copper wire would be a better choice. Wire from the hardware store will be over 99% pure copper. Stranded wire could easily be cut into small pieces that will more easily go into solution in the molten silver.
Copper pennies are hard to come by – recently minted pennies are zinc with a thin copper plating.
Larry Hanke
Minneapolis, Minnesota
1998
A. Hi Shelley. Larry has a good idea. The electrical conductivity of copper drops dramatically if it’s even slightly impure, so any wire you find will be very pure copper.
Pennies up to 1982 are copper, but not highly purified copper; after 1983 they are a thin copper plating over a zinc core.
While it’s probably okay to use pennies in science experiments without Big Brother actually caring, when you start melting down coins whose metal values are greater than their face values, we’re drifting towards a boundary line. If China bought up our pennies or nickels en masse at face value to melt them down it would be an actual problem :-)
Sterling silver is 92.5% silver and 7.5% other stuff; I think that “other stuff” is usually mostly copper. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
December 13, 2012
Q. To who it may concern:
I am doing a research paper on Copper Coins 1700’s, or 1800’s, or 1900’s century and need help securing this information. I would appreciate any help in writing this paper as I am a student at the University of Houston at Clear Lake. This paper is for a history/borderlands class.
Look forward to hearing from you!
Jowanna J [last name deleted for privacy by Editor]
– Sweeny, Texas
1999