#4168462 - 07/28/1011:01 PMRe: Mineral oil/Ultrasonic cleaner
If I just sell the car, I can up my bid...
It is carbonate verdigris.
Never use a dry toothpick and a dry coin surface to avoid damaging the patina. Put the coin into container of distilled water and let it soak for about five minutes. Then work on the verdigris while the coin is submerged. Always start with a gentle tapping motion to see if that works, then move to light rubbing if the corrosion is resistant.
#4168471 - 07/28/1011:08 PMRe: Mineral oil/Ultrasonic cleaner
If I just sell the car, I can up my bid...
Originally Posted By: M.H.
I held the coin with twizers and just swiched the coin in a small jar containing the Acetone. By the time I removed the coin and placed it on plate the coin was discolored (pinkish with one blue spot). That spooked me which is why I purchased a Sonic cleaner.
Acetone is safe for use on ALL coins. It absolutely will not react with metal. If your coin turned pink:
1) acetone impure (low grade or fingernail polish remover) 2) acetone contaminated or old and/or improperly stored 3) the coin had a previous treatment (e.g. artificial color, laquer, etc.)
I think the coin was previously treated. I tried the Acetone on some dirty 1970 lincoln cents and it cleaned them up without the color change. I ordered the Verdicare... Also, I really want to know more about ultrasonic cleaning. Anyone have successful formulas for washing copper coins?
Ironicly I was distracted by the first post in this thread and the last post asks the question I was originally looking for an answer for!
Anyone know any positive benefits for using a ultrasonic cleaner? Is it worth paying 120$US for a high quality machine with a 2 year warrenty? The seller says you can use any type of solvent in including industrial grade so i am not worried about damaging the machine so much as the coins!
Please keep in mind that I find it physically painful to work with items as small as coins in the manner of having to spend 5 minutes on one coin the way that was mentioned above. I may do it anyway for any more special pieces but I am really looking for a way to clean 10 or 20 coins without much physical fine motor skill labor.
And I am going to track down the Verdicare as I was impressed with those results!
#5969090 - 08/30/1205:58 PMRe: Mineral oil/Ultrasonic cleaner
Collector is an understatement.
The only method I use to "CLEAN" copper coins is this:
A good long soak in extra virgin olive oil. Most people have a bottle of this stuff sitting around getting rancid. The coin doesn't care how fresh it is, and the oil has a way of wetting the natural color of the coin so it looks rich & glossy, almost lusterous. After a good long soak, I will carefully remove the coin dripping with oil, and using a large stencil brush with natural hog or stiff camel hair bristles, I touch the tips of the bristles to the surface of the coin. Then, I apply a little pressure to bend the bristles and swirl the brush handle in a small circular motion both directions, while trying not to let the bristles move on the surface of the coin. This gently works the bristle tips into the cracks and crevises and helps to loosen up the soft gunk. You'll notice that the brush soaks up the excess oil from the surface too. If the coin was really dirty, alot of the loose stuff will be scattered all over the surface. I use a clean, dry soft hair makeup brush to brush away any oily surface dirt. After this treatment, check the surfaces with a high power loupe, and any remaining chunks can be gently poked with a rose thorn to see if it can be loosened. Done properly, this won't leave hairlines, and you should end up with a much nicer looking coin. I don't think this will do much for corroded (crusty) coins, but it might help to neutralize and stop active green corrosion. The brushes can be cleaned with acetone, but for some reason, I like mine with that green stained look - makes it work better somehow.
Also, just as a suggestion; Before you try this method, be sure to take a good quality photo of the coin. Then, after the coin is clean and pretty, be sure to take another photo in identical conditions, so you can compare the "before & after".