A weighty matter
Our pennies project has hit an interesting juncture. We've sorted through all of the thousands of pennies from 1981 and earlier, but now we've reached 1982. As you numismatists out there know so well, that was the year the U.S. Mint switched the metal in the cent from mostly copper to mostly zinc. But for that year, they made some of each. And to be a true coin nerd, you're supposed to save some of each.
To keep them apart, the most reliable thing to do is weigh them -- the zinc ones weigh just a little less than the copper ones -- and for that, one needs a scale that's sensitive down to tenths of a gram. Prowling around on the internet, we see that this kind of equipment is by no means scarce -- it must be a basic tool for drug dealers -- but we want to be sure to get one that will be accurate, if only for the hour or two that we'll be weighing a couple hundred pennies on it.
Readers, got any advice -- or a scale to lend?
Comments (10)
Perhaps some type of chemical test would be easier.
Posted by tom | November 1, 2010 11:38 AM
You can get a pocket scale at Harbor Freight on N. Interstate for less than fifteen bucks and if you cut out one of those 20% off coupons on their flyers it is about twelve bucks. Funny you should have the need for one, I just bought one there yesterday. I use it to weigh a bunch of scrap gold and silver I have so I don't get ripped off when I sell the stuff to a dealer. Mine weighs in grams, ounces and troy ounces. Accuracy is to a tenth of a gram.
Posted by John Benton | November 1, 2010 11:52 AM
I was going to say that any head shop carries electronic scales for about $20. Our local convenience store has some too. And of course, they also can be set for grams, ounces, etc. and fractions thereof. But you'd probably be more likely to go to Harbor Freight.
Posted by Bartender | November 1, 2010 11:58 AM
I still may have the scale I used in my darkroom to lend. It's a bit grimy from years of use, but the knife edge should still be ok.
I'll look for it.
Posted by Lawrence Hudetz | November 1, 2010 12:07 PM
You can buy an up to 0.1 gram accurate digital mini-postal scale on Amazon for as little as $6.15. See
http://www.amazon.com/Weigh-MS-500-BLK-Digital-Pocket-Scale/dp/B000P1NYE8/ref=pd_sim_sg_2
Or there is the old analog fulcrum model for $4.95.
http://www.amazon.com/Rollingforce-Silver-Postal-Scales/dp/B000UVNSRQ/ref=pd_sim_sg_3
Posted by Grady Foster | November 1, 2010 1:16 PM
Wouldn't it be cheaper to buy each of the 1982 pennies from a coin collector? If that defeats the purpose of collecting coins from your own circulation, you could take them to a coin collector at the store. They would probably help anyone that shows a new interest in collecting.
Posted by Travis | November 1, 2010 1:29 PM
If you don't have a tenth-gram scale handy, you can use the "drop" test. You need a hard Formica surface, a known copper penny, and a known zinc penny. Drop each one onto the table, listening to its distinctive sound. Zinc pennies have sort of a flat "clunk," whereas copper pennies have a higher-pitched, more melodious "ring" sound. Once you have a good feeling for how each type sounds, start dropping your 1982's one at a time, listening for the sound they make, and you should be able to sort them out by metal composition. Obviously, this test isn't as reliable as weighing them, but it should help you sort most of copper and zinc pennies.
Posted by dman | November 1, 2010 2:29 PM
you could also scratch a few (numismatic blasphemy) so the silvery zinc shows under the copper and pretty soon you'll start to notice that the copper ones and the copper-plated-zinc ones look very different
you do know that the copper ones have about 3 cents of copper in them, right? people all over the usa hoard them and sell bags of them. only about 20% of the cents in circulation now in major cities are copper
Posted by Sal | November 1, 2010 3:53 PM
One jar type for pre '82 and another jar type for post '81. Too much work to weigh '82s for separation. Other things to do is to continue stocking up on incandescents when on sale. Got about ten year supply right now, but want to get it up to twenty (Have until 2012, except GE is closing its one incandescent light bulb plant in the U.S). Fluorescents are too hard on the eyes, and from experience cause my wife headaches. LEDs are very expensive. Also, might want to maintain your 90 vintage cars as their gas mileage in some cases is actually much higher than newer cars of the same model type. For instance, our '95 Honda Civic gets 33 miles per gallon in and out of town, but our newer '09 Honda gets only 24 miles per gallon. Go figure.
Posted by Bob Clark | November 1, 2010 4:08 PM
Postage fulcrum scale is probably your cheapest bet if you're only weighing a few. Otherwise, I'd swing by a head shop and get a "postage" scale.
Posted by Chris Coyle | November 1, 2010 6:12 PM