Is Acetone really the trick?

I have a Kennedy half dollar that I pulled from a mint set that has some garbage on it and am wondering if Acetone is really the end all be all to getting this stuff off of there. I was painting some crown moulding and there was some gunk on there from a sticker or what not and I took my jar of acetone, wet a towel and it came RIGHT OFF! Is it the same for coins? I know you need to dip and not rub but could it be this simple? What I would really like to see out of this thread are some before and after photos if anyone has taken the time to do so!

 

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I am curious about this as well. I haven't tried anything with acetone yet but have heard people talk about it a lot here.

 

I never used it until today and it was on this piece of crown moulding. CRAZY how easy it took the gunk right off. It blew my mind how easy it came off of there!

 

Acetone is a good solvent for grease, oils, tape residue, glue, paint, pvc residue, and other organic contaminants, but it won't remove toning.

 

As long as you know there are health concerns due to the vapors being very flammable around a flame or spark, and that if you get it on the skin, it can remove the oils from the outer layer of dead cells ( corneum) if you are appearance conscious. Also do not put into a drain that uses PVC tubing ( some kitchen or bathroom sinks usually) for connections. It can not damage coin metals or metallic corrosion ( toning) in conditions you would live. In many labs with proper sinks, it is used in a squirt bottle ( with safety glasses) to clean test tubes that were used for organic chemicals. Best to first soak for a few minutes, then move coin to a new container with new acetone a few times to "rinse" off the gunk.
This will bother some people but!! Do not rinse with water after using , hold by the edge until the acetone evaporates as it carries any water in crevices of coin with it. You can find the MSDS on the web if you still worry about it. Do not use fingernail polish remover which contains acetone + additives. Any household that has 'superglue' in it , should have at least a small bottle of acetone in case some klutz glues their fingers together. Jim

 

Yes, it is. You can read all about it in the article I wrote here: https://www.ngccoin.com/boards/topic/146159-pvc-and-acetone-a-detailed-step-by-step-pictorial-guide/

 

@atcarroll has pretty much nailed it. I would add two points:

1) It's safe for silver, Cu-Ni and gold coins. Acetone doesn't interact with the metal; it only dissolves organic materials that are on the metal.

2) NEVER use acetone on an aluminum coin; it will eat away at and destroy the coin's surface. Also avoid using it on plated coins (e.g., brass plated steel).

Every raw coin I buy (except as noted in #2) gets an acetone bath before encapsulation regardless of whether or not there are visible contaminants, because I have no way of knowing what environment it's coming from. If from a smoker, for instance, it could have an invisible layer of nicotine.

 

Mint set packaging has destroyed millions of coins of various dates. The worst affected are the '68 to '71 and the '74 to '80. Many others are also badly affected but usually less so.

Acetone will often save some of these coins but I've found a better solution is about 80% isopropyl and 20% acetone. Let them soak for a few days. Be certain the alcohol is 91% alcohol rather than the diluted 70% because water will ruin clad. Don't let the solution get too old or the water concentration will rise.

Rinse them in warm water and spread them out on a towel to blot dry. Flip and blot a second time.

When this doesn't work (and it often won't) then the only thing left is a 1% solution of high quality ammonia and water. Dip briefly rinse immediately and blot dry. Caution; the ammonia will ruin the coins with significant exposure. Consider this process a last resort. Coins with much exposure will appear cleaned and the solution turns green. I tend to slowly increase the concentration until they are all ruined.

Probably all coins should be removed from mint sets and stabilized in alcohol. I wish I had done this to all my coins long ago. Alan Herbert suggested cutting the coins out right in the mint set packaging so a lot of my Gems are just ruined.

 

I'm not seeing how this could happen, and some quick Googling doesn't turn up anything relevant. Any links?

 

I have these before and after images.

 

After.

 

I believe some pure aluminum coins were coated with thin clear coat material to avoid rapid oxidation in usage. Acetone could remove these from older coins and they would oxidize haphazardly quickly. But it would not be only acetone, many organic chemical or cleaners could do the same thing. I do not collect foreign, so I do not know if the production process has changed. I buy it by the gallons and have never used it on aluminum coins, but never any effects from an undoctored coin. Jim

 

No links, just personal experience. I've destroyed two aluminum French colonial coins with acetone. It resulted in severe pitting.

 

If I saw that happen, I'd be very concerned that my acetone was contaminated, most likely with something acidic.

I just can't see a chemical path for pure acetone to attack aluminum. (But I'm not confident enough to risk anyone else's coins on it, never mind my own.)

 

I've been using the same acetone for a long time. The label says it's pure, and I have no reason to question it.

College was too long ago and my chemistry is too rusty, so I can't address if from a scientific standpoint. All I have to go on is firsthand experience. It's certainly possible there were extenuating factors, but nonetheless I won't risk using acetone on an aluminum coin ever again.

 

I guess if we ever go to aluminum , we will all find out for sure. In previous test runs. they specified T 5052 aluminum ( with 2.5% magnesium and 0.25 chromium) alloy.

 

Jeff, I don't know why it happens. But I can say with 100% certainty that I have done the exact same thing as Maxfli. I had one of the 1940's French colonial coinage that was aluminum (I think this one was from Madagascar). It was bright and lustrous, except for a small bit of PVC on the reverse. I gave it an acetone bath, as I do with all raw coins, and what came out was horribly spotted and ugly over the entirety of both sides. I wish I had taken pictures, but I didn't.

It's the same pure acetone that I use on everything else. I too was shocked by the result, and have no idea why or how it happened.

 

As somebody who hasn't run the experiment myself... it's time for various bits of aluminum around my house to start getting nervous. Also time for me to look for more acetone.

 

Right? LOL I thought about it myself. Hmmmmmm what can I dip that is aluminum!