Coin Cleaning - A Successful, Yet Controversial, Example

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I am opposed to cleaning or as some would like to call it conserving coins

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"Cleaning" should NEVER be equated with proper conservation of a coin as they are two completely different processes. Cleaning in the traditional sense involves removing metal from the surface of the coin- either through dipping, polishing, wiping, etc. The important point is that metal is removed and irreparable harm is done to the coin.

Conservation is and should be accepted through all fields of antiques including numismatics. Proper conservation should only remove surface contaminates from the coin and nothing else. This process prevents further possible damaging action on a coin without harming the coin itself. The problem is amateurs giving conservation a bad name by messing with it up and ruining a coin

Carl: Is there any way you'd recommend to possibly neutralize a coins surface from continuing to corrode, especially if this corrosive green stuff was removed? After removal, is there a procedure you would do immediately to help prevent further corrosion?

Naturally if you read me chemical reaction post of substances that effect Copper or Silver and even Gold, it should be apparent that the best method of protection is isolation. What I mean the best thing to do is preventing a gas or liquid to come in contact with any coin. Note that although people think Gold is immune to tarnishing, it will react with Sulfur type compounds. This would be a Br/Bk discoloration called Ag2S or Gold Sulfite.
Back to preservation. Note that on copper the first sings of exposure to the elements is darkening caused by the first Oxydation process. This is normal. However, if removed or the greenish patina is removed it is like polishing Silver utinsils where you must do it all the time or it turns black.
I've cleaned coins and then left them on a kitchen window sill to darken a bit. However, then into a Whitman Album or 2x2 folder. All my Albums are placed in freezer type bags with most of the possible air pushed out. My 2x2's are usually just stapled on 3 sides but if the coin is valueable the sides are taped with a clear tape in addition to the staples. Note air carries with it all the things you do not want coming into contact with coins. Some areas it is Sulfur compounds. Near pools that are chemically treated there is Chlorine in the air. Then there is that horrible stuff called exhaled breaths from people and animals. Now that is the stuff we must stop.
If you must clean a coin or just want to preserve any coin, just find ways to keep it from the air.

First, I would give a ride on my new Harley Road King for a copy of your formula, Rick. Seems that I remember you in a pic with a Harley posted here on the forum. Thought maybe I could tempt you. Regarding cleaning, I tend to agree that almost no coin should be cleaned, however, conservation done properly cannot be bad. In some instances though, cleaning becomes a last resort. I went to an auction a few months ago and bought a lot of copper large cents and other copper coins that were beyond recognition. Most were worn smooth. A couple had enough detail that they are in 2 x 2s and two of them looked like they had dried bubbles all over them. No detail was visible on either side, they were obvious metal detector finds. Before putting them in the jar for the nephews and nieces I decided to put them in olive oil first. Now, after about 4 months, they are both coming along nicely and I will post pics in about a month when I end the process. One of them is now 90% legible and is a 1864 Two Cent coin and the other is an 1829 Half Cent. It is simply amazing what olive oil has done for these coins. They have gone from being old discarded pieces of bubble gum to coins that I will be proud to show. Now tell me, how can cleaning off years of crude been wrong on these coins.I only wish I had taken before pics, but they were so bad I just never expected these kinds of results.
Jim
Hmmm, this thread got me thinking and I just checked the book. It would seem I need to go and see if the 1864 is a small motto.

Darn it, Large Motto.

A-ha!

Here's an 8 Reales piece from Lima, which is displaying some unusual characteristics. I wanted to see the damage, as well as surface characteristics under all that toning and used the above mentioned method to get the following results:





~Roman

Here's an article, outlining this procedure:

http://educ.queensu.ca/~science/mai...C03DEEA1.htm

Please use this at your own discretion.

~Roman

Carl, at 20x I saw nothing additional deposited on the surface of the coin. The only thing pointed to this procedure were a couple microscopic blueish "burn" spots where aluminum was in contact with silver during this electrochemical reaction. In any case, it served my purpose and I simply suggested it as an alternative to dipping (if one feels necessary to do so in the first place).

Myself, I appreciate a nice, "crusty", coin for my primary collection. I use acetone to remove organic surface contaminants from all my silver coins. When I worked in IT a few years back, we used pure acetone to clean glass strands for fiber optics, which was proven to leave no residue after evaporating.

~Roman

Roman, when you say pure acetone, is this the what is available commercially to the avg Joe? And, if not, where can you find it?
Jim