Cleaning extremely dirty copper pennies

[scyther]

Greetings, people of Realcent.

I just started hoarding copper pennies a few days ago (very small scale- I only have a few hundred- but better than nothing right?) and I noticed that some of them are so covered in grime that I can't even read the dates. Some are green, some appear to be covered in sticky tac, and some are just really dirty. So my questions are:

1. Should I clean them? I know cleaning coins can make them less valuable, but obviously these have no numismatic value anyway, so that's not an issue. But do they need to be cleaned? It seems like there's enough non-coin material stuck to them that it could affect their melt value. Or is that okay?

2. How should I clean them? I don't really want to go through scrubbing and peeling by hand if they're only worth one cent each. Can I just put them in bleach or something? Or will that eat away at the copper?

[Madwest]

Don't use chlorine bleach. That will coat the coin in copper chloride - a worse problem than the copper oxide you are trying to clean.

If you want to clean them for storage just for the melt value, you can soak them in just about any solvent to remove the stickiness. Stir with a wooden spoon. With enough agitation, some of the green corrosion might even loosen and rinse away. If you want them to shine, throw them in a tumbler (after they're dry from the solvent).

[galenrog]

Any good tumbler will do the trick. Tumble coins with a little soap to remove surface gunk, rinse, then dry thoroughly and then dry again. Did I mention to make sure the coins are dry before storing? A small desiccant pack in your airtight container of choice will keep your now clean coins from catching almost any kind of coin cancer once this is done. I keep mine in a safe, loose in boxes and bags, with a 20 watt heat stick to keep everything dry and comfortable for all my little metal friends

[jacer333]

Welcome, glad to have you aboard!

I know a lot of guys care more about the cleanliness of their coins than I do...I throw all of my coppers together. Some are bright BU's and some are ugly abes, but it evens out that way, right?

[galenrog]

To each his own on this subject. I do not clean even 1% of the coins I stack, but I do clean the worst of them, if there is no numismatic value in those specific coins. The coin guys I trade with locally do not really care as long as I pre-screen for dates and types they are after. I also clean gunky and cancer ridden coins destined to return to the wild. Kind of like rehabing an oil soaked sea bird. Clean it up, give it some love and return it to it's natural life.

[Rosco]

I agree rock tumbler a very little dish soap and pea gravel or quarter minus rock or aquarium gravel
dump on stainless or plastic coarse screen
rinse an rinse again then separate coin from gravel save the larger gravel not sand for next time
we have Laundry sink in garage
I spread the coin on plastic food service trays an let dry if tray has rough surface both sides of coin will dry in Garage fine
recheck the dates then store I'm using cent wrappers an coin boxes
I use a very small tumbler for up to 400 cents if not all are clean just run those again
light load is 75 cents
takes 3 to 4 hours tumbling then dry over night

[scyther]

Thanks for your responses. I don't have a tumbler so I used water and lemon juice. It worked pretty well.

But do you think they need to be cleaned? For melting, would it be a problem if a lot of stuff is stuck to the pennies, or would they be able to just melt them and have the gunk burn off or separate out on its own?

Just wondering if I should save myself the effort in the future.

[hammerrob]

Any penny that's so gunky that I'm tempted to clean it gets tossed with the zincs ... even if it's copper. I guess I've saved plenty of pennies that were only moderately dirty, and I'm not at all worried about them. They recycle copper pipe and who knows what kind of gunk is lurking inside of them. I'd begin to worry about my sanity if I was even considering investing time cleaning pennies. If you need something to fill your time sort, don't clean!

[Rosco]

Any penny that's so gunky that I'm tempted to clean it gets tossed with the zincs ... even if it's copper. I guess I've saved plenty of pennies that were only moderately dirty, and I'm not at all worried about them. They recycle copper pipe and who knows what kind of gunk is lurking inside of them. I'd begin to worry about my sanity if I was even considering investing time cleaning pennies. If you need something to fill your time sort, don't clean!

My dump bank is covered but finding coin to sort means a run to larger city thats fuel an lately at 20% cu not sure it pays

[penny pretty]

any penny I cant read date, I toss in jar with 82s. when jar is full I weigh them along with the rest. gram scale I got on ebay for 12 bux works awesome. I will CAREFULLY clean a nice older date with lemon juice.

[Numis Pam]

This is an old post but I am wondering if lemon juice is really OK to clean copper cents with? I would think it would damage them too as well as clean them?

[scyther]

This is an old post but I am wondering if lemon juice is really OK to clean copper cents with? I would think it would damage them too as well as clean them?

It definitely tends to stain them an orange-yellow color. I tend not to use it anymore. Anything worth cleaning is probably worth cleaning with something better. But if you have a bunch of generic coppers that are just covered in crud, it might be worth it to do a batch at a time...

[hobo finds]

If and when we can melt them mine are going with the crud on (more weight)!

[coppernickel]

First off welcome, good luck sorting.

If they are really that bad then I cleaned them by hand with some dawn dish soap. It cuts the grime really fast.

When they are this bad to begin with a little soap to find the dates helps. When the coin is that dirty and worthless soap is the least of the problem.

[realhumancopper]

Hi, does using something as coarse as peas gravel damage the tumbler? I have a very good rock tumbler and would not like to damage it. I know, it's for polishing rocks, but I would just like to be sure. thanks........h

[pennysman]

I use a tumbler rated for 3lbs. I fill the tumbler about half full of water, a big squirt of Dawn, about an oz or so of clean sand, and about 150-200 ugly coins. I run this anywhere from 4-8 hours, drain, rinse, spread out on towel and let dry until the next batch is ready. Been running about 3 batchs a day over the last month and cleaned about 15000 coins.

Steve

[68Camaro]

I use a tumbler rated for 3lbs. I fill the tumbler about half full of water, a big squirt of Dawn, about an oz or so of clean sand, and about 150-200 ugly coins. I run this anywhere from 4-8 hours, drain, rinse, spread out on towel and let dry until the next batch is ready. Been running about 3 batchs a day over the last month and cleaned about 15000 coins.

Steve

Got a picture of what they look like after that treatment? Curious to see the before and after. Is it worth the power to clean a buck and a half of cents?

[NotABigDeal]

I've thought about running some in my commercial vibratory polisher I use for brass. Makes the brass look brand new. Pretty expensive penny polisher though, hehe.

If I get some time I might try it.

Deal

[realhumancopper]

Hi, a follow-up: any thoughts to using a bit of vinegar or lemon juice in the tumbler? Also, coarse sand sounds better. I have the various grades for lapidary work. Thanks..................h

[DaMangRon]

I use walnut shell medium in a tumbler. Takes a lot longer than using soap and water....but I think it's a whole lot easier then having to worry about drying the cents. I'll run the tumbler for 24 hours and it'll get about 75% of the dirty copper clean. The remaining 25% just get stored separately.