I just bought a bullion piece that is 1lb Troy Silver. It's tarnished and seems to have other problems but I don't have it in hand. It came with the original COA and box as a limited edition. However it is a secondary item for a display, and I want to get it as clean as possible. I bought it as bullion, not a collectors piece. I'm not worried about it's resale value. I plan to soak it in an Acetone bath, but because of it's size and potential problems, I'm not sure for how long. I know if there are fingerprints they are here to stay. No problem with that either. I just want anything I can remove, off of it.
Have you read this thread? Seems pretty comprehensive... https://www.cointalk.com/threads/proper-acetone-procedure.193708/ or this one: https://www.cointalk.com/threads/acetone-questions.93332/
https://www.cointalk.com/threads/washing-silver-generic-rounds.275578/ Check out this thread. Last weekend I gave some silver rounds and a Canadian Maple an acetone bath for nine hours. They all had some nasty fingerprints that the bath completely moved! They are still not perfect but a vast improvement. The Maple came out the best. Did look like anything was done with it.
I knew about the 24 hour soaking time, I just didn't know how accurate that was and is it still the best information. I was planning to use a glass Mason Jar with the rubber seal and metal ring. They make short stubby wide ones. The less damage I may produce, the better.
I used a glass casserole tray and a smaller glass holder that I bought at Walmart very cheap. They worked fine. I did not cover them with anything, just left them in my living room with the sliding glass door open for good ventilation. I also Googled acetone for cleaning coins and got tons of information. A lot of it came from this site and other coin message boards. There were youtube videos too. Be Careful though as not all information is correct. I got a general consensus of what consistently came up as how to do it.
A day, a week, a month. Dosent matter and won't adversely effect the coin. Longest I've soaked is a week with a morgan. Did much more than just a few hour soak at removing a stubborn spot but still didn't remove it completely. Maybe I should be done a month long soak lol
Your best bet for acetone soak containers are larger shotglasses, which hold more than 1.5oz while still being small enough to force the coin to remain tilted and not flat. Any more than that is wasted acetone, because you do not reuse acetone after a soak. Acetone is a "total loss" conservation system. Always cover the container, from both a safety and economy standpoint. Bman's concept of leaving the container next to an open doorway is fine unless the wind is blowing in.... That said, one shot glass full of acetone is not going to burn your house down unless you're very diligent in your lack of diligence. Acetone doesn't naturally penetrate problems on a coin to the same extent that water does - part of the process of successfully using it is the "rinse/swish" step which gets short shrift in most discussions. To that end, soaks of more than a few days are probably useless; I've never gathered a bunch of problem coins in one place to do a controlled test of that idea because if a coin needs to go into acetone, it has a problem you want fixed quickly. Fingerprints are iffy. The permanence of their adhesion - and the time it takes to become permanent - are affected by the quality of the surface of the coin and its' preparation at the Mint. A little contamination already on the coin will prevent a fingerprint from adhering for a while; the more clean and pristine the surface, the quicker a fingerprint will become permanent. And keep in mind, acetone is an organic solvent. Non-organic chemical processes - "tarnish" - are unaffected by it.
SuperDave; The one pound silver bullion coins are 3 1/2 Inches in diameter. They would not fit in a shot glass?
My bad. Not used to thinking on that scale. Point stands about getting them into a container of the right diameter to force the coin into a "reclining" position without it laying flat. In your case, that might have to be a 55gal drum.
MS 70 works pretty well on silver depending what the tarnish is and wouldnt require a giant tub of acetone laying around.
I don't believe what has arrived. This seller would have gotten at least $100 to $200 more for this item if he took better pictures. That includes my bidding. I don't have to touch a thing. What a relief. I have the original unblemished die that struck this piece, and along with this great looking bullion coin, (COA and Original box), I plan to leave this to my grand daughter who was born on the same year. I can't believe in all the luck involved in both purchases. I am a happy camper. :>) :>)
I posted the die already under exonumia. I need a little time to take a picture of the bullion. I'll try and get it up tonight. Thanks to everyone who had the courtesy to reply.