Cleaning Help Please...

[ferdware]

Hello everyone,
I was recently out at an old plantation dating back to the 1700's. I was using my V3i in Salt Beach mode.
I found some nice items. One of which was what looks like a old copper coin. It is completely green and I can not see anything to tell for sure. Can anyone tell me how to clean it.

thank you
Ferd

 

[a4wdguy]

Use warm water, a soft toothbrush, and hand soap to remove the dirt. Do not try to remove the green patina.
Get an electric potpourri warmer from the dollar store and a bottle or two of hydrogen peroxide.
Heat the peroxide to boiling in the microwave.
Place the coin in the warmer and plug it in.
Pour the peroxide over the coin, submerging it completely.
When it quits bubbling, dump the old peroxide out and examine the coin. If it still has dirt, GENTLY roll a q-tip over it.
Put fresh boiling peroxide in the pot and soak the coin some more.

The peroxide will remove only dirt. It will not harm the patina.

 

[ferdware]

Hi and thanks for the info.
but actually, I am trying to remove some of the patina. It is so thick that I cant even tell if it is a coin for sure. I would like to remove some to be able to see what it is.

Ferd

 

[burlbark]

Place the coin in a tablespoon of olive oil and heat it till it boils. Then drop the coin into cold water while it is still hot. Be careful with the olive oil, It may catch on fire but dont panic with it. I use another moisture free utensil to slide the coin out of the olive oil into the water. Repeat as necessary. Works every time for me.

 

[nw1886]

If the patination is so thick as to have totally obscured the details, be careful with that last step and stop when it starts detracting from any detail gained with the process. (I do conserving of ancients at work and you can easily "blow through" anything gained!) Baby steps...baby! (Mantra from work. )

 

[Larry (IL)]

The best you can hope for is to clean the coin Ferd. The patina is part of the coin now and all of the details are in the patina, if you take that off, you will end up with just the ugly core of the coin.

 

[Neil in West Jersey]

All of my dug coppers get soaked in a hot hydrogen peroxide until the coin stops bubbling. I heat up the solution in a microwave safe bowl until it bubbles, and then I add the coin. Sometimes I need to wipe the coin with a q-tip dipped in the solution to remove the lingering dirt.

The problem with the olive oil is that it cointinues to leach out of the coin for a long time. Here are some results. The last one was one that sounds like you describe. It had a thick coating from mineralization interacting with it: