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Cleaning corroded pennies and coins
An ongoing discussion from 2004 through 2016 . . .(2004)
Q. I'm a parent, working for a small booster club. A local mall has generously donated money from their wishing well. There are a lot of coins and the money nice but the only way the bank will take it is to have it cleaned up. The water has corroded and pitted the pennies (silver coins were easy to clean). My question is, if there is a something that divers use to clean corrosion off copper- like pennies? We have tried all the science fair type of solutions, but there are bags of pennies. Is there a way to remove the corrosion and save the penny. One mother is using a very strong bathroom cleaner that is for removing rust deposits from sinks. If you leave the pennies longer than 30 seconds they go black.Mrs. Yaple
parent - Lewisville, Texas
A. When the mint needed to change pennies from solid copper to copper plated zinc in 1982 because of inflation, the durability of pennies sitting in a wishing well could not be at the top of their priorities. The pennies corrode horrendously and it's not always a simple matter of washing or cleaning them if they have become seriously disfigured by corrosion. Hopefully someone will have a helpful suggestion, but visit the US Mint website -- maybe they have a program to give credit for unusable pennies?
Ted Mooney, P.E. RET
Pine Beach, New Jersey
A. This information still came up on google. It was helpful and led me to the us mint website, where I found out this (direct quote from www.usmint.gov):
"Mutilated Coins: United States Coins no longer fit for circulation are classified as "uncurrent" or mutilated.
Uncurrent coins are coins that are worn yet recognizable as to genuineness and denomination, and are machine countable. Uncurrent coins are redeemed by the Federal Reserve Banks, then forwarded to the Mint for disposition.
Mutilated coins are coins that are chipped, fused and not machine countable. Mutilated coins are only redeemable through the United States Philadelphia Mint facility.
All uncurrent or mutilated coins received by the Mint are melted and reused in the manufacture of coinage strips."
So, in the original situation, possibly sending the corroded pennies to the PA mint for redemption may be your easiest bet.
- Yorktown, Virginia
A. Possibly- a small tumbler with a plastic media- Might work.James Watts
- Navarre, Florida
A. There is a product available called, curiously, Penny Brite [linked by editor to product info at Amazon] Cleaner/Polish that does a good job on copper & copper based alloys (brass, bronze). Unfortunately Ted is correct about the current copper plated zinc pennies. Maybe you should campaign for the U.S. Mint to take this junk back at face (?) value.Ray B Anderson
retired metallurgical engineer - Kent, Ohio
A. I'm not sure if this is totally applicable, but I was watching a show related to soda and it's effectiveness in cleaning pennies. Apparently, soda (or cola, pop) is really good at getting off all the "tarnish". Just a thought.
Good luck!T.B. [last name deleted for privacy by Editor]
- Wheeling, Illinois
A. A dry tumble in walnut shell will more than likely get most of any "wishing well wish residual" (sorry, I couldn't resist) off. After that, try a mixture of Muriatic Acid [linked by editor to product info at Amazon] in a warm water bath. I don't see you needing any more than 10% acid to the solution.Russell Ackerknecht
- Greenwood Lake, New York
A. Try ammonium citrate- mixture of citric acid and ammonia(25%)-5% solution is good(dissolve 50 gms citric acid in 1 lit water,add ammonia to pH 9). If this looks complicated 5% citric acid also must work.Goran Budija
- Zagreb, Croatia
Q. I have corroded pennies that have excessive scale and deposits built up on them. They were removed from a drain line after about a year of submersion. Some are melded together - too bad to even attempt clean up. But most of the others could probably be salvaged if I could come up with a good cleaning solution for severe corrosion and concretion build up.
I will try a 5% and 10% solution of Muriatic acid, both with and without salt as an additive and post the results soon.
- Warrington, Florida USA
Hi, Roy. Pennies since 1982 are made of zinc, which I believe will dissolve rapidly in muriatic acid. I think it won't succeed and may be dangerous, but good luck!
Ted Mooney, P.E. RET
Pine Beach, New Jersey
The suggestion is sound and not theoretical, I assure you. I've been using this process for years and the pennies will not degrade in any way shape or form.
- Greenwood Lake, New York, U.S.A.
February 10, 2008
A. You can clean pennies in ordinary ketchup. Just empty a bottle into a large bowl and dump in the pennies. Give them a stir and wait a bit. Bright and shiny in no time.Kathleen Benedick
- Baltimore, Maryland, USA
April 27, 2008
I just tried using ketchup to clean pennies and found it worked quite well.Rusty Morris
- Half Moon Bay, California
February 26, 2008
Q. I tried cleaning old wheat pennies with vinegar and salt and the pennies turned a dull pink in color. Is there any way to restore the pennies, or at least make them shiny again?Micah Glover
student - Birmingham, Alabama
February 26, 2008
A. Vinegar and salt is mild on people but exceptionally aggressive on copper and brass, Micah. Try a commercial copper cleaner instead. A mild one like Brasso [linked by editor to product info at Amazon] will restore the warm color of the penny soon if not immediately.
Ted Mooney, P.E. RET
Pine Beach, New Jersey
March 3, 2008
Q. We received over 70 pounds of corroded pennies for the Pennies for Peace project. Anyone have an easy way to clean that many?Richard M. Dailey
- Huntsville, Alabama
April 29, 2008
Q. We have a number of coins that were exposed to salt water in Hurricane Katrina. Some of them are silver that we had bought as investments (silver dimes/dollars), some we had "left over change" from trips overseas many years ago, but none necessarily valuable.
I would like to know how to clean them. Some have a bright aqua coloration; some (an Eisenhower dollar, for instance) look like they have rust on them. Can you give me some suggestions, please? I have already tried baking soda and a toothbrush. Thank you.
- Upland, California, USA
June 24, 2008 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. I have been given a few thousand pennies that are very tarnished from a fountain in a mall. they were given to us for a veterans memorial to clean and cash in. Can you tell me what will clean them PLEASE!Tom Wilkins
hobbyist - Hot Springs, Arkansas
A. Go to fountaincoins.com. They are a company that cleans, counts and banks fountain coins for you for a small percentage [Ed. note: 25% of the recovered amount]. Saw them on "Modern Marvels", "coin op" episode.Gary Uhlan
- New Haven, Connecticut
December 14, 2014
They clean bulk coins bulk coins with no numismatic value.
- Texas USA
Oxiclean 7.22 lbs.
A. Well everyone, you all had great ideas! However, my favorite method is Borox and Oxiclean.
I recently found a Bunch of pennies while cleaning out an old trailer and they were in Awful condition. Some were stuck together or unidentifiable. I put them in an old peanut butter jar and tried a number of cleaning techniques: Hot Sauce- did ok on the ones that were just tarnished but didn't help corrosion. Diet Soda- made a small improvement on the corrosion but not great. Vinegar- just seemed to tarnish them more. Sand & Soap tumble- Nope, didn't do much.
Borax did excellent, was cheap to buy in the laundry aisle, took off quite a bit of corrosion, brightened up the pennies, provided an abrasive to tumble them in while it worked its magic + I added Oxiclean to help remove organic goop too. About 5 tbs borax per quart of water and about 2 tbs Oxiclean if you like.Valerie Herman
- Mesa, Arizona USA
April 21, 2016
Hi Everyone! I was looking up how to clean corroded pennies also, because I enjoy saving change, and I had some money get damaged and money is already nasty to touch anyways, and this just made it worse to handle them! I appreciate ALL of the suggestions since I have already tried and tried doing whatever I could to clean them. I could have been lazy and taken them to one of the casinos since I live on the River City and probably traded them in, but I'm determined to clean these Myself. I have traded in rolls of change at the casino before, but unrolled they probably would not have accepted this nasty change! I kept thinking about using something with citric acid in it or vinegar, so since some of you have used the "ketchup method", I believe I will put on some rubber gloves and give it a try first from all of the above answers! I appreciate the advice that EVERYONE has provided! What would We EVER do without the Internet??? The Walking Dead is VERY educational about survival and other things and NOT just about a bunch of zombies fumbling around, LOL! I am a SURVIVOR! God Bless You ALL and thanks again!!Amanda Adele George
- Vicksburg, Mississippi USA
July 11, 2016
Q. I found a roll of new $1 (gold colored) coins in my shed. They are sooo rusted; they were still in wrapper. Put them in vinegar, not much help. Help, it's $25.00michael f chalifoux
- langhorne Pennsylvania, usa
September 18, 2016
A. I am in a Club that receives fountain coins from a local casino for our fund raiser. (This is what we were doing today, cleaning coins.) We usually handle an average of $4,000.00 dollars worth of coins per year. It doesn't seem like a lot until you start cleaning them. Usually, we do a Muriatic Acid wash (agitated with a cement mixer), then a power washer rinse cycle, then onto drying and sorting them.
When using this method you have to separate the pennies from the silver coins, otherwise you will have a bleed over. The coins are still not in like new condition but they are legible and legal tender. We do have a member who purchased a polisher and tumbles the silver coins with pulverized corn cob. She stated that she leaves the coins in this polisher for about an hour and it does greatly improves the look of our silver coins. Our problem is mass production, this polisher is not capable of handling vast quantities of coins at a time. So, for those of you who are not dealing with large quantities of coins this might be another alternative for you without the mess. I have read in a post above this one where they used Borax and Oxyclean. I am going to try this one to see if it can handle our bucket loads.Lori Silverstein
- Saint Louis, Missouri