Understanding Cleaning

Thank you Sap for the information. I used the Acetone and it cleaned my coins nicely. I have a clearer view of the coins.

Still learning!

Now - I have beautiful pics of all of these coins and they are too big to down load. I may just have to buy a coin camera.

Olive oil is slightly acidic and promotes pitting/reveals hairlines. This may adversely affect silver coinage.
Silver=Acetone, Methanol, or Acetonitrile
Copper=Olive oil preferred by some b/c it leaves behind the aforementioned protective layer/film and Cu is more resistant to it's effects.

Which one would be good to remove the black residue the is always along the date, IGWT, Liberty, and the mint marks on copper? I just know that a couple coins I have are doubled but the black stuff is hiding it. I have been using witch hazel to clean them but it is not getting rid of the grim.

Never use Olive Oils on any coins. For one thing not all Olive Oils are the same. Like any product that is manufactured by different organizations, their methods of productions are different therefore the end results can vary dramatically. If you were succesful in removing anything with Olive Oil you now have a cleaned coin and it can be easily detected by any grading service. The removal of many contaminates on coins removed some of the metal of the coin and this is also detected. Then naturally there is the slimy leftover from the oil which now has to be removed with something like Acetone and then rinsed with distilled water. Now here is the problem with Acetone. Purity. If you purchase Acetone from the normal paint section of a store, you have no idea how long it has been there. Being a great solvent it may have alrady started to disolve some of the inner lining material from the can. The way to check for this is to put some on a clean glass dish and allow it to evaporate. If there is any residue at all, discard this Actone as contaminated. Many people have tried the Olive Oil treatments and have many different resolts due to different items in the so called purified or Virgin Olive Oils. Ever wonder about the different containers of Olive Oils? Some in cans, glass jars, plastic bottles, etc. And how long was that oil in that container? Be carefull using anything that people recommend on your coins. They are your coins and if things go badly, they are still your coins and not replaceable by the people that said to try this or that.
The thing to remember is not all subtances are the same even though they may have the same names. Sort of like not all vacuum cleaners are the same although they are all vacuum cleaners.

Yeah, very good advice Carl.

Denatured alchohol works great on any coin to remove gunk/dirt/etc. It now replaces the need for me to use acetone.

Another poor idea. As with any product as I mentioned previously about Olive Oils, manuafacturing processes vary and the end results also vary. Do not use chemicals to clean coins unless you just want a shinny coin of no value. If you ever watch the Antique Roadshow on TV you would have noticed how many times they state "If you had cleaned this, it would now be worthless or close to it". This is extreamely true of coins lately. Back in the old days, cleaning coins was the thing to do. People used to want bright shinny stuff. However, as the coin collecting became so much of a bug business, cleaning coins had become the thing not to do.
You must remember that many of the items you see on a coin as a contaminate has become part of the coin. It usually is a chemical reaction with some other substance. Removing this contaminate will take part of the coin with it.

I too have noticed the differences that different brands and strenghs of olive oil and how it affects the coin. I soak in olive oil just enough to soften any goo in order to remove it. Still sometimes it affects the coin in ways that alters it's tone and which I am not pleased with.
I'm going to use distilled more frequently rather than olive olive in the future.

Also, I agree with Mike's post above.

Another problem with olive oil, besides the variation in ingredients already mentioned, is that it can slowly oxidize, forming lacquer-like substances that may never wash off (other hydrocarbons such as gasoline do this if you leave it in a gas tank for a few months).

As a chemist (and not a coin-cleaning expert), I like acetone a lot better than water, since water facilitates many other reactions (acid etching and oxidation both go faster with water). If you did use water, I would use acetone last (again subject to the high purity warnings already mentioned. I use high-purity stuff at work, which is far more pure than distilled water).

I use acetone to dry things. It washes off the water, evaporates quickly and cleanly, is extremely unreactive, and won't dissolve metals, metal oxides, or metal sulfides (which pretty much describes coin surfaces). Of course, that's not to say when you make a loosely attached particle fall off it won't take some metal with it and be uglier underneath.

Denatured alcohol is different things at different times, often with water, so I don't trust it.

I'd also avoid anything that was stored in a plastic bottle. Not only can the plastic add to the residue problem over time, but most plastics are permeable, so even if the plastic has no additives, that adhesive from the label could eventually soak through. I work with eye-drops, and after years of finding things in the eye-drops that passed through the outer box, through the label, and through the bottle into the solution, I'm surprised they keep the water in. Oh, actually they don't. Many of the bottles lose 5% of the water contents per year, straight through the plastic, concentrating the ingredients by 5% a year.