Soaking silver in olive oil to eliminate hard green stuff
OriginalDan
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I have a few chopmarked coins that at some point developed some hard green gunk on their surface. I've soaked them in olive oil (EVOO) for the past year and it doesn't seem to have done anything to soften or loosen the green stuff. The green stuff is really quite hard, harder than a wooden toothpick I've used to try and get it off the surface of these coins.
These aren't extremely valuable coins so it's not a huge deal, but I'd like to learn how others deal with this hard green stuff. Anyone have luck removing it? Anyone know what it is?
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What a coincidence. I think I may have the answer as to what that hard "green stuff" on your coins is. The latest issue of the scientific journal, "Inside Proboscis" arrived in my mailbox just this past week. There is an article in this month's edition about the history of the handkerchief, of all things. It's seems that during the colonial period in South America, and also during the same time in parts of Asia, the handkerchief was somewhat of a luxury item. Seems strange but according to the research, it's true. The upshot to all of this is that since hankerchiefs were in such short supply, people often resorted to the closest thing at hand, their fingers. No pun intended. So...... that hard "green stuff" that's causing you so much grief my just be fossilized....well, you know. If that is the case, you might want to refer the situation to your local pharmacist. Hopefully, he can recommend an over-the-counter product that will soften the hard green stuff and make it easy to remove. You're welcome.
Have you tried ms-70 solution ? It might help. Just a thought.
Good luck and please do let us know what you come up with.
The first thing I'd try is a solvent that works on organic matter, acetone, xylene, etc...to try to dissolve it away. It might just soften it up enough to allow a toothpick or rose thorn to do its job.
I'm sure you know that if/when the green gunk is removed prominent spots are likely to remain. But, as you said, they're not very valuable so the risk isn't big.
Lance.
I have removed stuff like that using acetone. Be sure to use a glass container, do this in a well-ventilated area (preferably outside) and be patient. This might take a couple of days. However, you might not like what you see underneath....
RMR: 'Wer, wenn ich schriee, hörte mich denn aus der Engel Ordnungen?'
CJ: 'No one!' [Ain't no angels in the coin biz]
It he above post seem to be right on.
Take their advice!
Thanks for the input guys. I had previously tried acetone and it didn't help, but I only soaked the coins for 10s of minutes at a time. I suppose an extended soak might be more effective. I'm not too worried about spots remaining, the coins are already beat up from the chops. More trying to preserve a few pieces of history and prevent an future damage/growth.
Question, how do you prevent the acetone from evaporating over the course of a few days. It's cooler now, but in the summer I've seen a small glass bowl of acetone evap in a matter of hours.
Also, congrats on 13k Lance.
The last time I did this, it was as a favor for a former Forum member. I did it in my lab. using warm acetone (I am a chemist by training, and used a hot plate) and it took several changes of the solvent, some patient picking with toothpicks, and the better part of a day. I think that you didn't wait long enough. Since you don't have access to a chemical lab (I assume), I would use something like a caning jar with a lid. If you cannot find decent grade acetone, methyl ethyl ketone will do.
RMR: 'Wer, wenn ich schriee, hörte mich denn aus der Engel Ordnungen?'
CJ: 'No one!' [Ain't no angels in the coin biz]
I use these bowls. The lids are LDPE so they are impervious to acetone. Also super inexpensive.
Collector, occasional seller
I use a small porcelain bowl and an old Redbook to lay over the top. The plastic cover seems to create a really good seal with the lip of the glazed ceramic.
I haven't tried leaving acetone in there for days, but I have left coins in there for at least a day and didn't notice any significant change to the acetone level.
I've used a pyrex kitchen bowl with a glass dish on top and a weight on that and soaked coins overnight. I don't think several days would harm the coins, either.
Even long soaks in acetone will not harm the coin....acetone works on organics not metal. A magnified shot of the 'green stuff' might help us to better identify the problem. Since you are not concerned about the surface, MS70 may also help. Let us know (and show pictures if you can) how things progress. Cheers, RickO
It sounds like the "hard green gunk" may be verdigris. If so, acetone will not likely work on it because it is not organic. More commonly seen on copper coins, it can also form on silver coins because of the copper alloy in most of them. I have seen it on Trade dollars. There are products out there that specifically treat verdigris (e.g. Verdi-gone, or something like that); I have never used any of them, so I can't vouch for how effective, or how damaging, they may be.
mbogoman
https://pcgs.com/setregistry/collectors-showcase/classic-issues-colonials-through-1964/zambezi-collection-trade-dollars/7345Asesabi Lutho
Verdigone (now "Verdicare") works really well on newer verdigris. It struggles with much older, hard spots.
It won't hurt the coin even if it is ineffective. It's a coin treatment product somewhat like Blue Ribbon and Coincare.
Lance.
You might want to try a long soak in VerdiCare as well. Couldn't hurt. However, whatever the substance, it might be a permanent feature at this point.
If you want to play around with **those particular coins **, keep soaking your coins in, VerdiCare, baking soda, tap water, soap and water, distilled water, olive oil, salad dressing, etc. Oh, and everyone's favorite time waster ACETONE! Acetone has its place in conservation, just not here.
Buy some MS-70 and stop the games.