HOW TO – Make a penny shell

HOW TO – Make a penny shell

 Popsci Images 2007 07 Penny 485
Here’s how to to make a penny shell (using acid to dissolve the zinc core) –

Looking for something more interesting to do with that jar of pennies than just cash it in? One word: acid.

In most years before 1982, American pennies were 95 percent copper. Then the price of copper went up until you could get $100 worth of pennies at the bank, melt them down, and sell the metal for more than $100. So the government started using a core of cheap zinc with only a thin plating of copper.

The fact that pennies are made of two different metals opens up the interesting possibility of separating them.

GRAY MATTER Pretty Penny – Popular Science – Link.

12 thoughts on “HOW TO – Make a penny shell

  1. maken says:

    This is very cool, but whats even cooler is if you were to do this in a bottle and put a balloon over the mouth to capture the gas being generated you would have hydrogen which is even more buoyant than helium…
    watch out for any flames though, hydrogen is super flammable …Boooom!!!

  2. Yagomatso says:

    United States Code
    § 333. Mutilation of national bank obligations

    “Whoever mutilates, cuts, defaces, disfigures, or perforates, or
    unites or cements together, or does any other thing to any bank bill,
    draft, note, or other evidence of debt issued by any national banking
    association, or Federal Reserve bank, or the Federal
    Sucks that this is a felony. Oh no! Run!

    Reserve System,
    with intent to render such bank bill, draft, note, or other evidence
    of debt unfit to be reissued, shall be fined under this title or
    imprisoned not more than six months, or both.”

  3. philliptorrone says:

    i’m pretty sure the u.s gov has better things to do than arresting, prosecuting and jailing a scientist for showing how a penny is made.

  4. Windell_Oskay says:

    You can do a similar trick with heat instead of chemicals. First, you nick (or file) the edge of the copper as Theodore Gray does, then hold it with tongs in a hot flame, like that of a propane torch. The zinc has a much lower melting point than the copper and, when it melts, just drops right out of the copper, leaving the thin shell. (The zinc is hot when it falls out– you need to make sure that there’s a safe landing pad for it before you do this.)

  5. Tapanageta says:


    “…with intent to render such bank bill, draft, note, or other evidence of debt unfit to be reissued…”

    It’s meant to stop you from destroying huge amounts of money and thus destabilizing the economy. Dissolving one cent is not going to put all the banks into default.

    Incidentally, in some places the law only prohibits you from destroying or defacing money if you still intend to use it as money. If you’re destroying it for some other reason, it’s legal. That’s how the companies that make the souvenir coin-flattening machines get away with it; it’s implied that by making a souvenir you aren’t going to try and return your penny into circulation.

  6. Bananna Co says:

    Melting down a penny ain’t gonna hurt anyone but how about a million pounds? On August 23rd 1994 the K Foundation (an art duo consisting of Bill Drummond and Jimmy Cauty) burnt one million pounds sterling in cash on the Scottish island of Jura. This money represented the bulk of the K Foundation’s funds, earned by Drummond and Cauty as The KLF, one of the United Kingdom’s most successful pop groups of the early 1990s. The duo have never fully explained their motivations for the burning.

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