fundraising with copper

For my community-service group, I recently looked into the effectiveness of a suggested fundraiser: a penny drive. Pennies are easy donations because they're virtually worthless, so no one thinks twice about unloading them.

However, the particular idea here was not to deposit the pennies into the bank, but rather to melt them down for their high-value copper. Copper is becoming rare, so its value has been steadily increasing (which is why you hear about people pilfering copper wire and copper pipes from construction sites and other unguarded buildings).

My first question to ask was, how much is the copper in a penny actually worth?

The answer isn't straightforward because pennies have changed over the years. When pennies were introduced in 1793, they were pure copper. Here's the history of the metal makeup by mass:

1793–1857: 100% copper
1857–1864: 88% copper, 12% nickel
1864–1942: bronze (95% copper, 5% tin and zinc)
1943: zinc-coated steel (steel is iron and carbon)
1944–1946: brass (95% copper, 5% zinc)
1946–1962: bronze (95% copper, 5% tin and zinc)
1962–1982: brass (95% copper, 5% zinc)
1982 on: 97.5% zinc core, 2.5% copper plating

As you can see, the pennies in 1982 and beyond have a trivial (and unextractable) amount of copper in them, so the first step of the fundraiser would be to separate the pennies into "pre-1982" and "post-1982" bins. The ones in the "post-1982" bins would be deposited in the bank directly. (Though, actually, when the value of zinc increases enough, it would be worth it to melt them down for that.)

Before 1982, pennies had a mass of 3.11 grams, so the amount of copper in them was 95% of that: 2.9545 grams. A first-order search for the current value of copper gave me around $1.70 per pound. 2.9545 grams of copper is then worth 1.1 cents.

A 10% return on investment isn't bad (especially when the principle is donated!), but the next consideration is volume. To raise an appreciable amount of money (say, $1,000), we would need to collect over 90,000 pre-1982 pennies. That's 623 pounds of pennies. Nobody is about to carry that around. Worse, pre-1982 pennies are less common than post-1982 pennies, so we would have to collect more than twice that number.

At this point, this fundraising idea started to look not very feasible.

But then I found the real killjoy to this fundraising idea: it's actually illegal to melt down coinage now. The U.S. Mint anticipated people would try this again and made regulations to prohibit it.

Oh, well. Onto the next idea.