Cleaning old copper

MICHAELDIXON

Today was a busy day for me. I had breakfast with Charley from the boards, and, let me tell you, he is the one of the most knowledgeable people I've ever talked with. Each time we have breakfast or lunch, I learn so much. He can quote information on silver dollars that boggles my mind. Not only does he know silver dollars, but other series as well! If you ever get an opportunity to talk with him, take it!
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I had lunch with a "Senior Citizen" of the numismatic community. We were talking and I asked him how people 'in his day' cleaned copper that was dirty, green, etc. Surprisingly he told me and I went back and tried it with great success.

Here is his secret:
1. bring water to a boil with salt in it,
2. Place the copper coin in the boiling water and let it boil for one minute,
3. Take the coin out, cool it and rinse with water and dishwashing liquid,
4. Coat the coin with Crisco cooking oil and let it soak for several minutes,
5. Use a paper towel and take off the Crisco.

I tried it on some old, green, dirty large cents I had around and it amazed me! They came out looking decent.
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Don't try this on coins that are worth certifying! Try it first on a coin you can afford to destroy. Your results might be different than mine!
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Dinner was fantastic! I'll make another post about a friend of mine who collects antique furniture that I have gotten into coins. You will be amazed at what he found in an antique shop!

Neptune

thanks for the tip - I think I may put on a pot of pennies (cents that is). Another thing that I do for ones that aren't really worth anything is a dab of mineral oil on a Q-tip, and/or toothpick. Guess that works like the Crisco.

MICHAELDIXON

To the top.

ss350camaro

Thanks Michael

kryptonitecomics

Very interesting technique..........I'd be interested in other ideas on the subject!!!

hookedoncoins

Interesting, indeed. And the crisco doesn't leave the coin somewhat oily after the wash?

dorkkarl

if you really wanna have fun, when you boil the coins, add a generous helping of vinegar.

K S

LanLord

<< <i>if you really wanna have fun, when you boil the coins, add a generous helping of vinegar. K S >>

I believe vinegar will make the copper turn puke-pink.

Not the desired result

Cam40

ever try goo-gone? seems to clean brown copper without changing color...initially that is.
years from now they may turn dark,who knows..

then theres always the acetone dip. most swear by it. MOST, not all.

DesertRat

In the Tarnex commercials the coins they dip look real nice!

MSD61

Olive oil also works good as well.

dorkkarl

<< <i>I believe vinegar will make the copper turn puke-pink. >>

heh heh heh.....

K S

lordmarcovan

Sounds interesting.

I've used the salt water solution with electrolysis, but never boiling.

This did have some unfortunate consequences once, as I just posted on the "numismatic mistakes" thread a few minutes ago:



<< <i>Another numismatic mistake I made was attempting to use electrolysis to clean a crusty large cent I'd found with my metal detector. It was the first large cent I'd dug, and when it came out of the ground, I could see it was a Draped Bust. Detector finds, particularly crusty copper, must be cleaned, so cleaning it was not a mistake, but using the electrolysis was. My homemade electrolysis rig worked splendidly on silver and had even done well on some copper in the past, but I guess I left the large cent in the solution a little too long, and when I "zapped" it, what little detail that remained on the coin just crumbled away- I'd "burnt it up".

So now I have a Draped bust slug. Just a featureless, pitted brown disc. Even if the cleaning had worked as planned, it probably would not have been a great looking coin (after all, it had been buried for 200 years), but I sure would've liked to have been able to make out the date on it.
>>



I guess the Crisco performs similarly to the Vaseline I often use.




I posted my "Potato Trick" for crusty dug copper on the MD forum. It also works for those uncleaned ancient bronze coins. But this is just for crusty coins like detector finds. Wish I'd done that instead of the electrolysis on the large cent I mentioned above.

I used the "potato trick" to good effect on these large cents my friend dug (after he sold them to me).

1798/7
(This is the one that was in Coin World a while back, but the picture there is awful.)

1819 (scan)

1819 (camera)


Think I might try the tip you just posted on some of the larger lots of cheaper old Brit pennies I get periodically- it'd be nice to be able to treat more than one coin at a time.

earlwbollinger

Wow that's a interesting scanner there. It actually hides the roughness and pits on the coin.
My scanner tends to highlight all the imperfections.

MrSpud

Here are a couple of fun related links. One is an experiment for children to clean copper and includes discussion on what happens if you don't rinse the coins well afterwards Making Pennies Shiny with salt and vinegar and the other shows a video of someone fisrt artificially oxidizing copper to make it black then making the black oxidized copper turn red and shiny by gassing it with hydrogen while it is hot Making black oxidized Copper Shiny with Hydrogen

lordmarcovan

<< <i>Wow that's a interesting scanner there. It actually hides the roughness and pits on the coin. >>



It's not so much that, as the fact that the angle and lighting/shadows in my amateurish photo made them jump out more. Though it does have some roughness and pits on it (most notably a shallow cut on the rim), you have to admit that that is one helluva nice looking copper, considering it spent so long in the ground!

The photo is more accurate than the scan, though. It is a little weird that the scan sort of softened some of the flaws (and details) of the coin. I didn't mess with the image's focus, as I recall, but if I had, I would've used the "sharpen" command rather than the "soften" command.

dollardude

Thanks, Michael, for some good advice. I'm not a copper expert, and this is helpful.

<< Olive oil also works good as well. >>

I've also heard this advice for copper from articles on archeological finds.

lordmarcovan

Olive oil is a tried-and-true favorite of collectors, and has been used for years, if not centuries. I find it leaves a bit of a sticky residue sometimes, though. I find Vaseline less messy. But olive oil is better for soaking, of course.

mrearlygold

I "helped" my older brother out when I was home sick from school as a boy by using a pencil eraser to clean his "dirty" lincoln cent collection.

Woweee was he so happy after he came home and found out about my helpfulness.


Tom

MICHAELDIXON

This information might be useful to some.

jmski52

Be careful to remove the Crisco residue. I am fairly certain that Crisco (and olive oil) will both contain some small amounts of fatty acids, which would be corrosive (especially to copper) in the long run.

Your final consideration would be either an acetone rinse, or warm soapy water (I would recommend Johnson's Baby Shampoo or Joy Liquid - neither of them is derived from a saponification process that involves acidic components) with a fresh water rinse. Pat dry with a clean, soft cloth.

I know that they soak some encrusted ancients with olive oil for a period of time, and I am sure that it simply to help loosen the debris.

PerryHall

I would love to see some before and after pics.

MICHAELDIXON

Wow! I cannot believe I posted this over 4 years ago!

ksteelheader

<< <i>Wow! I cannot believe I posted this over 4 years ago! >>



Hi Cuz!!!

Dave99B

Yikes.....paper towels are highly abrasive!

Dave

MICHAELDIXON

Good information. And remember this line in the post:
Don't try this on coins that are worth certifying! Try it first on a coin you can afford to destroy. Your results might be different than mine!

PerryHall

<< <i>Yikes.....paper towels are highly abrasive! >>



Paper towels are fine if you blot the coin. Just don't rub it.