A week in acetone - now what

So I bought this specifically because of the gunk that was on it, as I wanted a nice condition coin to 'fix' with acetone. It was/is my practice coin. The fact that it was $4 (or maybe it was $6) helped too.

I soaked it in 100% acetone for about 2 days, with the occasional swishing, but I wasn't seeing the gunk dissolve of fall off. I took it out and ever so gently rubbed it with my thumb, and got quite a bit of it off. I put it in fresh acetone, and let it sit for a few more days, and got a bit more off. It's now been in the acetone for a full week, and I can't for the life of me get the rest off.

What would you suggest I try to get the rest off? I did resort to a Q-Tip (cotton swab), and a toothpick, but my goal is to get it clean without it looking cleaned.

BEFORE:

AFTER A WEEK:


WHAT STILL REMAINS (huge bump in saturation to bring it out for easy viewing):

 

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I suppose you could just put it in even longer... But a full week is already pretty crazy.
I'm not sure what the effect of mineral spirits or something like that is for silver coins.

 

I'm pretty sure that's the limit of what acetone can do. It looks like whatever the substance is has etched into the silver surface, hence caused permanent damage. That said, well done in removing most of the gunk out!

 

@BadThad @Kentucky @SuperDave any thoughts? Xylene? Water soak then Xylene?

 

Xylene may help. It works differently than acetone, so if the residue didn't completely dissolve in a polar solvent it might come off with a non polar solvent.

You may be able to get rid of the yellow/brown spots, but as @gxseries said, there may be some permanent damage under them

I've never used Xylene, but was under the impression that it has a few more safety concerns than acetone (which is flammable), so check out if you need any additional precautions beyond those needed for acetone

 

http://www.lincolncentforum.com/for...0-The-First-Steps-to-Proper-Coin-Conservation

 

As it looks like it has been taped onto a sheet or coin page due to the residue. I suggest boil it in hot water an make the glue residue very soft...Then scrape it with a toothpick until it moves. Do not use a pin as metal against metal scratches badly..However you cannot make it any worse than what it is..The numismatic value has completely gone as it has been cleaned before and lustre has vanished....Just imagine you have polyurathane on your hands after varnishing some wood. You would wash them in hot water and detergent. Use an old scrap piece if fabric ( preferably cotton or toen bed sheet ) as it would be soft..Just remember these all here from other people are suggestions...WE ARE NOT TELLING YOU WHAT TO DO as one should never clean a coin.... However you will do as you wish...OIO

 

Yes, try xylene and then i would do a short acetone rinse and follow up with distilled water.

 

Acetone also can be used for detecting watermarks on stamps

 

Shoot, wouldn't that stuff dissolve the stamp? After all, the stuff eats through Styrofoam........

 

The classic fluid for detecting was carbon tetrachloride, but that has been banned. Should probably go with a non-polar liquid that will wet the stamp but evaporate quickly. Lighter fluid works well I have heard.

 

Green 18 Nope...for some reason the paper gets darker and the watermark just shoots up so clear...
Kentucky, as for lighter fluid, that normally costs more than acetone...I have also used rubbing alcohol which i normally only use on my computer screen and scanner and that works as well...I tried in on a noemal stamp i use on letters. I dont know why, but acetone is normally bought in metal tins where alcohol can be found in plastic bottles....They both smell nice tho....lol

 

I hope this question is germane enough to be okay in this thread, and I was happy to see that my first correspondent here, @Kentucky , was mentioned as an expert on this subject.

As I was looking through this jar of Wheat Cents I have sitting in my office, I noticed a badly corroded coin that was off color compared to any old penny I have ever seen. When I looked closer, I found that it was not a penny at all, but a German 5 Pfennig coin, and an old one at that, complete with swastika. The coin is obscured by a lot of caked on something so I cannot read the date on it. I have no idea what the metallic composition would be, but it, obviously, falls somewhere between 1933 and '45; from its condition, my guess would be that it dates from the Thirties. So, what chemical might you apply first to see what's underneath all that gunk?

 

I would say it is made of brass but as the coin is now too far gone, i would place it under militaria..... if you want to sell it on ebay, go into that area as the coin collector will not want it with all the vertigris.... BTW, no one is an expert in anything...It is simply the amount of experience one has had in the field.... I have had over 50 years practise in the foeld but i do not claim tho be an expert... Try to soak it in very hot boiling water and soften up the stuff on the coin, then use a toothpick as wood does not scratch metal.... It will not take 5 minutes

 

I'm no expert either, @oz_in_ohio , but I recall one of my teachers in school 60-some years ago who was lecturing on the dangers of drinking Coca-Cola, pointing out to us that an old Penny left soaking in the dreaded drink could restore the coin to its original brilliance; just think what it was doing to one's stomach. My doctor warned against drinking any of that swill years ago, so there's none here to use in that experiment. Besides, If my memory is correct, the people who concocted that stuff monkeyed with its formula back in the 1980s, so it may not work with today's product as well.

 

Water (and soap) will remove things that organic solvents won't touch.

Also, how about lacquer thinner? That contains toluene among other things.

3M makes a solvent for weatherstripping adhesives, that is amazingly good at removing "goo" from things. Very pricey though. They sell it at automotive paint product "stores".

 

I personally wouldn't try anything else. Hell, if you've had it in acetone for a week, just put it in your pocket and carry it around for awhile and move on to your next coin.

 

Expert??? Expert!!! Thanks for the laugh. If the coin you are talking about is whitish, it could possibly be one of the zinc coins. Zinc coins are extremely hard to do anything with in my experience. the Coca Cola soak is sometimes successful due to the presence of phosphoric acid in the drink and also to carbonic acid in the carbonated water. Phosphoric acid is also found in Naval Jelly (if you know what that is). If the coin is pretty well gone, nothing much can hurt it. Try boiling water, try soap and water, see if they do some good...BTW a good scrub brush for coins can be made by cutting the bristles of a toothbrush to half length so they are stiffer.