General Questions On Acetoning A Coin

Whatever you chose to do.....make sure you have plenty of ventilation!

I have read most of the threads, but I can't recall seeing any advice on getting the coin in the acetone. One thread said to put the coin in a container just big enough for it to fit, but how then do you dip the coin? I don't want to fingerprint the coin taking it out.

Use a ceramic coffee mug or bowl. The simplest and cheapest way is to get the coin out is from the edges. This is a common practice at many coin shops.

Whatever you do, don't let the acetone touch anything made of polymer or plastic. That includes a painted, varnished or laminated benchtop or floor surface. If it must come in contact with plastic, test it first before using it with coins.

Use a glass or china/ceramic container to hold the acetone while you're dipping. A saucer or clean ashtray would suffice; if you use a container that's too deep, you can't get the coin out again easily with your fingers.

I would suggest getting yourself several similar dishes or bowls, and pouring most of the acetone from one bowl to another as you work. For getting the coin in the acetone, I'd suggest placing the coin in the empty dish/bowl you're using, then pouring in enough acetone to completely cover the coin. To get the coin back out again, either fish it out with your fingers (gloved) or decant most of the acetone into another container (don't pour it back in the bottle; it's now been contaminated), then picking the coin up.

If you're still worried about touching the coin (or you haven't found any suitable gloves) just place some soft cloth, tissue or towelling on top of the coin, and invert the bowl, so the coin "falls" into the cloth. Again, if you use a cloth, test it with acetone first - acetone is also very good at sucking unfastened colour out of cloth; you're trying to clean your coins, not cover them with dye.

I would recommend using gloves while dipping coins in acetone. Not because acetone is deadly if you touch it (it isn't, really) but because it'll suck the oil right out of your fingers and, if you're not careful, deposit that oil right onto your coin. First, test the acetone on the gloves - after all, the gloves are going to be made of polymer or plastic, which I've just told you to keep away from acetone. Rubber, latex and nitrile gloves should all be fine; but PVC gloves are likely to dissolve on you.

Like schmidty said: a fingerprint only damages a coin if the print oil isn't removed straight away. If you do mishandle the coin while you're doing this, rinse the coin again with acetone to wash the print oil off.

Isn't that as bad as cleaning?

I have cleaned the PVC green residue off of hundreds of silver coins using clear amonia with incredible results. When I tried acetone I couldn't get the same results. The coins need to be placed in a glass container with a slightly rounded bottom. Some coins will clean in 5-15 minuets and some will require hours of soaking. The ones I did show no negative issues even under a strong magnifying glass. Once soaked, remove and lightly roll a Q-tip but don't rub, then place in another glass container with distilled water and soak for a few minuets. Place the coin on a very soft sloth and pat dry. The amonia stinks as well but without the dangers of acetone. It will not change the toning.

Actually, ammonia should be OK to use on silver, or circulated silver at least; ammonia is the standard cleaning agent for ancient silver coins freshly dug out of the ground. I wouldn't recommend it for any other metal, unless you've tried everything else and it hasn't worked. It will almost certainly radically alter the appearance of a copper/bronze coin - fluorescent orange colour is not uncommon after an ammonia dip. I'm not sure how well it does against sticky PVC residue, since ammonia mainly reacts with corrosion byproducts. I'm not sure I'd trust it on an Unc or Proof coin.


It is "cleaning", but not in the usual sense that non-collectors use the word when talking about having old coins that "need cleaning" - by which they mean the metal isn't shiny anymore. Acetone won't make a dark, oxidized coin shiny - it won't remove toning/tarnish, it won't remove a fingerprint that's been there for more than a few weeks, it won't remove corrosion or corrosion byproducts or restore corroded surfaces. It will only remove organic residues - and here I'm using "organic" in it's chemical sense, meaning carbon-based compounds.


That's exactly the kind of coins that "should" be acetoned. Acetone will shift "organic compounds" - PVC plasticizer residue, paint, varnish, ink from a marker pen, that sort of thing. If acetone doesn't move it, and doesn't at least start to move it within seconds, it's not organic, and further soaking in acetone isn't likely to help. I suspect the "green stuff" on southerngent's coins either isn't PVC residue, or is residue that's so old the active, organic components have all reacted with the metal or evaporated and there's only corrosion left behind - if the plastic and metal were in contact for a very long time, the damage has already been done.

A coin badly affected by PVC residue will very likely look "hazy" after being acetoned - this is inevitable; the "green stuff" is green because it's reacted with the metal, causing corrosion; that metal had to come from somewhere. Acetone cleaning is all about stopping further damage from occurring - if the green goo is left there, the coin will only deteriorate further. In that sense, it's "conservation", not "cleaning".

Silver doesn't normally turn green (unless it's .500 fine or lower). PVC contamination is the most common reason why it would, which is why "acetone" is the standard response to "green stuff on silver coins". However, if it's actual corrosion, caused by something else, then acetone isn't going to help.