Reading through the different viewpoints with acetone & xylene for copper coin preservation, but I'm curious about using either to a larger scale. I've acquired several large albums packed with hundreds of beautiful older copper coins, but its not been properly stored for quite some time and the pages have a slight tackiness to them and you can see a very slight green tint on the edges of many coins. Should I put each coin into a small glass jar with either acetone or xylene and let it sit for a day or two and then let them dry for another day before putting into a new flip?
Acetone I've had experience with, but never with copper. I've only soaked silver in it, and in a glass jar. My results vary as the acetone will only purge the organic materials and do little or nothing with the toning. Terminal state toning becomes non-effective in reaction to the acetone. Xylene I've had no experience with but I have read that it must be used with caution. I have no idea of the reactionary results with copper. Hopefully, others more knowledgeable will check in with their opinions. Those are some interesting coppers you have there, my friend. Welcome to the mix........
Welcome to Coin Talk! The best advice I can give you is to take your time and be cautious. I would not use acetone on copper but I have heard xylene is safe. Any time you do large scale anything there will be casualties, so if you truly care for preserving your coins do them individually. Every coin can have its own special considerations. What it sounds like is: you have to remove oxidation and/or grit, crud, debris. You must be careful not to scratch the coin while you remove any debris or grit, and you must learn how to do that on an expendable coin test subject before you ruin any of the collection. Soaking in distilled water, patting dry and never rub the coin. More members will chime in with more advice. Good luck…Spark
I don't think your proposed large scale method is going to work well. I am somewhat assuming the method would be placing 10/20 pieces at a time in a solution. Unless you are absolutely certain of what substance is on each piece (and there will be many substances you will not be able to identify and on many pieces it may not be visible if there is a substance but there is), you are risking contamination of pieces in the same container. 1/2/3, maybe 4 pieces at a time that you are sure is not a contaminant that will create a large scale brewery of liquid that could be detrimental to other pieces, while certainly time consuming, will be a safer method. Who knows? You will maybe identify an anomaly that captures your attention and curiosity will trigger your interest in reading a Book on the piece and learn valuable information and knowledge. The only other suggestion is dump a bunch at a time on a comfortable play time rug and invite 5-10 ankle biters over, because it is 100% certain the majority will place a few at a time in their mouth and "wash" them with some great solvent cleaners present in their saliva. Yes, a few may swallow a piece or 2, but what the hell, when playtime is over, you will have processed quite a number of pieces saving you time and effort. This has been another Charley Talk. YW.
I have used acetone on hundreds of copper coins with no problems. I have a group of shot glasses of different sizes. I pick a size that only lets the rim of the coin touch the glass. It takes about 1 to 1.5 oz to cover the coin. I use an old glass flashlight lens to cover the shot glass and let it soak for a few hours, no rubbing of any kind. The glass lens will let you pour off the used acetone. Next you let the coin slide out of the glass onto a clean cloth. The rims of the coin are the only thing to come in contact with anything. Now you clean all the glass with water and a clean cloth. Next I give the coin a second bath with fresh acetone. After a while, I put a drop of this used acetone on a glass slide or mirror and let it dry. This will let you see how much junk is still floating around in the acetone. Coins with heavy PVC may require several baths. My last step is to pour more fresh acetone over the surfaces of the coin and let the coin dry on a clean cloth. In my 40 years of doing this, I have never harmed a coin but sometimes the surfaces of the coin that were under the PVC are already damaged and ugly. No amount of conservation can fix that.
Each coin to its own separate container. And you only need enough to just barely cover the coin. For a more detailed description - https://www.cointalk.com/threads/proper-acetone-procedure.193708/ Since you're dealing with copper, follow the same procedures with xylene that I described for acetone. Also, with both acetone and or xylene, you always need to use in area that has good ventilation.
To be fair, I agree because I routinely use acetone on copper and copper-plated coins. But occasionally one ends up with a bluish sheen so I mentioned it as a measure of caution…Spark
