A question about dirt on pennies

[hatpin]

On pennies that have dirt that will not come off, is that because of corrosion under the dirt?

Ive been soaking an 1901 Indian head in water , that has fantastic detail. Liberty is plain and all the detail in the feathers are visible. Its not a valuable penny so Im trying to clean it for myself ,not to sell. I take it out every once in awhile and pick at the dirt with a toothpick. It has reached a point that no more dirt comes off. Im wondering if its corrosion that has the dirt encrusted.

 

[Jason in Enid]

It is most likely only corrosion left. The thing with coppers, is that they often get that deep, green patina to them. That patina IS a corrosion layer. Removing the corrosion will reveal a very rough and ugly coin underneath.

 

[Critterhunter]

Try heating it up over a candle and then throwing it in cold water. That will shock the junk off it. Also, after you clean a copper or bronze coin rub some olive oil on it to bring out the detail and protect the coin from oxidation. Some people carry a jar of water with them in the field to throw the coin in right away as some will degrade when exposed to the air. It protects it from degrading until you can clean it and rub olive oil on it. Some people like to soak copper or bronze coins in olive oil for months to remove the junk on them but I've never had much luck with that.

 

[TerraDigger]

Use a clear oil to soak (cooking oil). If olive is used, get as clear a type as possible. Heavily colored olive oils can discolor the coin. Also, change the oil as needed as the gunk/corrosion (usually green colored) from the coin discolors the oil & this may also discolor the coin.

 

[hatpin]

Dirt doesnt come of pennies like it does silver. Its dirt that I see. Why does it stick like cement?

 

[TerraDigger]

Because pennies chemically have a higher corrosive potential than silver coins. Thus 'dirt' as you refer to it, binds more strongly to pennies.

 

[Fabio]

I prefer to wash my copper or bronze coins with hand soap, since I like the blue-green finish to them. I also wrap the coins in wet tissue paper to keep them wet until I get home, although the coins I found recently were already dry-crusted, due to the local drought... It's been showering the last few days, but the ground is still very dry under the grass.

 

[edjcox]

Go to a pharmacy and get some mineral oil to soak your coins. Use the olive oil for cooking..
A very mild solution of lemon juice will also asist but watch carefully as that is an acid... To neutralize dip the coin in a solution of baking soda...

Another way to clean is tumbling the coin in a tumbler filled with BB's or Steel Bird Shot. Don't overdue it.

 

[MNCoinhunter]

You can use Brasso on pennies with good results. Just drop a gob on there and spread it around. After a few minutes you should see the Brasso lifting the crud off ... rinse under water and repeat until you get the desired results. Keeping in mind that it will eventually take the patina off if you leave it on there for an extended period of time. Definately NOT recommended for key-date coins ... which should'nt be cleaned in the first place.

 

[Tin Fin]

Hydrogen peroxide cleans em pretty good - I would leave whatever color is left, on them. I would never use brasso on anything other than clad though - dipping coins cleans them, but de-values them too. Overcleaning does the same.