Loc: Texas and other furrin places
I have never tried to clean a coin with acetone (or MS-70 for that matter), but I have been given a few coins that are just plain ugly as they are and need help so I can enjoy them ...
for instance this silver German 10 Mark 1972 Olympic Flame ... a historic coin with an otherwise excellent strike and lots more mint luster than appears below
So, my question is in the normal practice of using acetone, I know to soak and not wipe, but in what type of container (glass, covered?) and for how long? I have also read that you should rinse it with fresh acetone when you take it out.so residue just doesnt redry on the surfaces. Any other guidance?
Lastly, if it came to using MS-70, what is the best use practice for that as well? And what metal compositions is it safe to use on?
I'm no expert but I saw a post here that suggests to use "pure Acetone" not nail polish remover, soaking for 20 minutes, then rinse with distilled water. If the coin still has an undesirable appearance then try 24 hours in the Acetone followed by distilled water. The third option is Xylene, then Acetone then distilled water. No rubbing, no paper towels. Just air dry.
For coins very lightly affected the distilled water may be all thats necessary. This process will not work on copper.
Loc: Texas and other furrin places
What I have learned ....
Acetone cleaning is a relatively safe way to remove built up remove oils, dirt and residue from silver and gold coins, hovever it's safe use on copper coins is not fully agreed upon at this time*. It can both dissolve lacquer that was used on some older coins and also remove a green film on coins damaged by storage in polyvinyl chloride (PVC) holders.
While using the proper technique you can improve the appearance of your coins safely and effectively, this method is not recommended for your most valuable coins. If this is the case, or if you do not not know the value of your coin, please consult a professional conservation service instead.
What you will need: ...... acetone - can be purchased at most hardware stores. Do not use nail polish remover! ...... small glass jar, dish or flat bottom bowl**. Do not use plastic! ...... latex gloves and eye protection ...... wood-cored cotton swab. Do not use plastic-cored swabs! ...... distilled water ...... soft cloth
1. Work in a well ventilated place. Acetone is flammable and the vapors are harmful.
2. While wearing gloves and protective eyewear, place the coin into the glass container. Clean only one coin at a time to avoid friction between the coins.
3. Pour enough acetone into the container to completely cover the coin (~ 1/4 inch).
4. Avoiding fumes, gently swirl the container to loosen any PVC slime or debris.
5. Allow the coin to sit for a minute. If this is insufficient you may consider resoaking for up to 20-30 minutes.
6. Remove the coin carefully while wearing latex gloves.
7. Rinse the coin with a small amount of fresh acetone.
8. (Optional) If any residue remains you might consider using a cotton swab, dipped in acetone, by either "rolling" the swab or gently dabbing at both sides of the coin to remove any remaining residue. Do not scrub at the coin or use a toothbrush as doing so can leave hairline scratches. If the coin has a lot of residue you should replace the swab frequently. Rinse with fresh acetone.***
9. Rinse the coin with water and blot it dry with a soft cloth.
10. Finally, let the coins air dry before returning them to storage.
Remember to store the used acetone in a sealed container or dispose of properly.
** With most jars it is difficult to safely place, remove or turn the coins.
*** If a residue still remains try soaking the coin again in a sealed container for 24 hours before attempting the rolling maneuver again. If rolling still fails, try more intensive, higher-pressure "dabbing", but if the residue still doesn't respond it may not be possssible to clean your coin using this method.
Loc: Texas and other furrin places
Thank you, BartlesvilleOK ... I try to be careful especially posting something like this. I still havent found a suitable container for my little experiment on the 10 Mk coin above, but I will post a picture after I try the proceedure out. When I first saw the coin it was clean (believe it or not) so it may be environmental danage rather than organic debris. We will see
What I'd suggest is to retrieve a coin from soaking with a pair of tongs (by it's edges obviously) perhaps rather than a gloved hand as ANY rub will harm the luster of the coin instantly making it an AU. Similarly, regarding the idea of swabbing the coin, all you can do is really lay the wet swab in place. Again, any rubbing will instantly cause luster issues and will create hairlines.
Finally, PVC over time will "eat" into a coins surface. You may successfully remove the offending slime however, it's damage may be permanent. Even a flawed coin is better than scrap in most cases.
Thanks for all the information. I signed on tonight to try to understand how a thin film of whitish looking stuff gets on proof coins. In my case, the capital holders are original and I was sending some of the coins for grading to increase (hopefully) the value.
If you look at the coin at a slight angle you don't notice the film at all. Just beautiful mirror finish in the fields. If you put the holder under a strong light ( I use an Electrix 5x power inspection rig to (amateurishly believe me) estimate the grade of the coins.
So.... Three questions Has anyone had this same experience? If you attempted to clean with the acetone process, was it successful? If you sent the coin off to be graded would the coin grade?
Loc: Western Washington
I have soaked an AU 1857 FE (S-12) Cent for about a week which had some small PVC stains on the reverse in a hermetic jar partially filled with USP Acetone. The coin luster was affected by the soak and turned BN from RB. I then let the coin soak in almond oil for several more days which brought back some of the luster but the coin was still BN and will be forever, unless I doctor it which I do not even know how to do.
The coin was sold to me as a problem free AU58+RB raw and I did not notice the very small spot on the obverse (an attempt to cover tooling marks to remove PVC and using dyed putty as cover) for several months after my purchase. I soaked it until the putty feel off because the dealer had already doctored it to a nearly worthless condition. I now own the coin by default because I trusted this dealer's reputation and the coin is now in an AU Details holder which maybe I could sell for maybe half what this dealer charged me for a righteous coin.
These are the smallish and somewhat expensive tragedies of collecting which I have not even bothered to write the dealer about. I just figure that money is more important to him than honesty is and I will, never buy from him again. This is presently the only coin that I own which is in a details holder because I got cheated. The few other examples acquired from other "honest, large and reputable" dealers left my collection an earlier date. Good riddance to bad rubbish! I am sure that all old time collectors have some of these tales of woe.
I have been collecting coins for more than 50 years and can grade very well for most series that I collect. My personal weakness is trusting dealers just because they are big or have a "good" reputation. In every instance, it has been a "honest" dealer who cheated me, either by ignorance, by not being too concerned about the quality he sold or by offering me a return on merchandise that he had no intention of honoring.
Therein lies the need to recognize your own limitations, and be willing to have professional coin grading services grade select pieces instead of insisting on everything raw "like in the good old days." Of course they can make mistakes too -- but it's another layer of protection.