Letter Re: A Practical Use for Post-1982 US Zinc Pennies

I just discovered your site this afternoon and look forward to perusing it in depth. I noted your response to the question about hoarding dimes and your reference to the metal content dollar value. Let me pass on a tip: hoard up a several pounds of pennies. Here’s why.

As you know, pennies are roughly 97% zinc and 3% copper. To that mixture, one may add a few aluminum cans and minor amount of copper wire to bring the mix to 93% zinc, 3% copper, and 4% aluminum. This alloy melts at relatively low temperatures and is called “Zamak”. Zamak is a light, strong, easily castable alloy that because of its “campfire” range melting temperature is just the ticket for replacing small metal parts in a pinch.

I keep a bucket of pennies next to the lathe just for this purpose. Although from a “coin melt” perspective this [stockpiling of recently-minted pennies] may look like a loser, it’s a huge bargain when you consider the cost of having the [UPS] boys-in-brown deliver you copper, zinc, and aluminum ingots. – J.W.G.

JWR Replies: I had never fully considered the casting possibilities of zinc pennies with a home sand-casting foundry. I’m a tinkerer art heart, so henceforth, I’m going to save all of the pennies that I get in pocket change. I’ll simply leave them all unsorted for now. I suppose that I’ll eventually have my kids build us an inexpensive low-volume penny sorting machine, to divide the sheep from the goats. That is, sorting the early 95% copper pennies from the newer (and now more-common) copper-flashed 97.5% zinc pennies.) Thanks for that suggestion, and welcome aboard!