PVC and Acetone - Part 3 of a 3 Part Series: Using Acetone

[physics-fan3.14]

Finally, Part 3 of my series on PVC and Acetone.

You can find “Part 1: PVC”, here

You can find “Part 2: The Science of Acetone”, here

 

A number of people have asked how to actually go about using acetone. When I first started using it, I was rather nervous about it myself, concerned that I would damage one of my coins. But with a little reassurance, and practice on a cheap coin to get familiar with it, anyone can perform this very simple and very important conservation.

 

My roommate recently asked me to go through his small collection of coins and catalogue, appraise, and conserve those that needed it. Among them, I found this 1850 large cent, and realized that it was in dire need of help. As I was going through my buddy’s collection, I noticed several of his coins were in very old plastic flips, and that some of them were growing green spots. There were three things that alerted me to the presence of PVC: 1.) The green spots. 2.) The plastic felt soft, pliable, and slightly slimy. 3.) The flips (and coins in them) had a faint smell that reminded me of a new shower curtain. This is a great diagnostic, since many shower curtains are made from PVC.

 

The holder, with coin removed. Notice the bright green film on the inside of the flip, where the coin was contacting the plastic.

 

 

Before pictures of the coin. Notice the reverse was far more seriously affected than the obverse. There was still a film on the obverse, but not nearly as bad. The reverse had a very thick film which was literally obscuring details. I was somewhat nervous about this, I was afraid that the PVC might have already started eating into the surface of the coin. If this happens, the damage is irreversible. But, removing the PVC and preventing further damage is still necessary, in my opinion.

 

 

So, I got a glass and put about a half inch of acetone in the bottom, and gently set the coin in. Do not use anything with dyes or plastics, because acetone will dissolve any plastics (including supposedly indestructible Nalgene bottles.) A clear, shallow glass or porcelain bowl is the best. Also, make sure that you set the coin in gently to avoid splashing or damaging the coin. I would also recommend doing this over a paper towel, and not over a surface you care about much. I once spilled a couple of drops on a wooden table that was varnished. One use of acetone is to remove varnish, and the spot on the table was stripped. So now I do it at my cheap particle board desk, where I don't care if there are spots or scratches. Anyways, here is the coin in the cup of acetone:

 

 

After letting it soak for a few minutes, I pulled it out. Acetone is perfectly safe on the skin, although I wouldn't recommend washing your hands in it regularly. But fishing a coin out won't hurt you. It will feel very cool to the skin because acetone evaporates very quickly. This is the same basic principle why you sweat - the evaporation cools you.

 

Perform this next operation over your paper towels, because you don't want to damage the coin if you drop it. Take a Q-tip, dip it in the acetone, and gently wipe the surface of the coin. Q-tips are soft and absorb well, and shouldn't damage the coin unless used too roughly. Dipping the Q-tip in acetone will also help to minimize friction, and will allow spot removal at the point of contact. The acetone will evaporate from the surface of the coin very quickly, and will evaporate from the Q-tip rather quickly as well. When the head of the Q-tip begins to dry out, just dip it back in the acetone again. As you wipe the PVC from the coin, the Q-tip will become green. When you see it green, or possibly brownish, just replace it. See below for what I'm talking about. The top Q-tip was only used briefly, but the PVC was so thick on this coin that I had to replace it. You don't want to continue re-using the same Q-tip because you don't want the PVC removed to be deposited back on the coin. You also don't want too much of it to be re-dissolved into your acetone as you are dipping the head to rewet it.

 

 

Keep wiping (gently) until the Q-tip no longer turns green. If there is still PVC on the surface of your coin, just set it back in the acetone for a little while longer. Depending on the thickness of the contamination, it might have to be there for a long time, and you might have to repeat numerous times. For this coin, I had to repeat many times: I used about 25 Q-tips over a period of three days and several changes of acetone. After a little while of soaking and wiping, I noticed that the acetone the coin was sitting in started becoming cloudy. It also began to diminish in effectiveness, so I poured out the cloudy acetone and replaced it.

 

 

Be careful that you don't leave the coin in the acetone overnight, unless it’s well covered and there is plenty of acetone in there. I made this mistake and woke up to find all the acetone gone, and much of the PVC that had dissolved in the acetone had been redeposited on the coin. There was a thick film of slime all over the bottom of the glass, and on the coin. Luckily, this PVC was not bonded strongly with the coin, and so came back off quickly.

 

About halfway through the process, you can see noticeable improvement:

 

 

So, after a couple dozen Q-tips, three or four changes of acetone, 4 days, and probably over an hour total of wiping, washing, and examining, this coin was salvaged. I was quite pleased with the results; it turned out to have not been damaged significantly by the PVC. The surfaces were a little dull, but major damage was avoided. I managed to rescue a decent looking, albeit well circulated, large cent. This was by far the worst contamination I had ever seen, but it turned out well.

 

 

So, if you have anything else you would like to point out, I welcome your comments. Conserving your coins is important - you wouldn't want your Picasso to be hidden under dirt and grime that would damage it. Likewise, you don't want your coins, no matter how common, to be hidden under PVC that will eat holes into them. This is an important function as we are only temporary holders of history - there have been numerous people who have owned this coin before us, and there will be many more people to own this coin after us. It is our responsibility to make sure that it lasts in good condition!

 

Jason Poe

[Oldtrader3]

Thanks Jason, more good information about soaking for longer term periods to remove embeddded PVC from coins. The only thing that I would add about using acetone is the fact that it is very flammable and should, for that reason be used outside, or in a well ventilated area because or flash danger (no smoking around it). I do not like the fumes and keep it sealed in a hermetic jar while soaking a coin.

[physics-fan3.14]

Thanks Jason, more good information about soaking for longer term periods to remove embeddded PVC from coins. The only thing that I would add about using acetone is the fact that it is very flammable and should, for that reason be used outside, or in a well ventilated area because or flash danger (no smoking around it). I do not like the fumes and keep it sealed in a hermetic jar while soaking a coin.

 

Excellent points, which I mentioned in Part 2, but deserve to be repeated here.

[michael]

excellent experiences with corrosponding photos (thumbs u

 

all 100% true

 

as this has been my experiences exactly like you have done and i also made the mistake of letting it evap overnight and had the green slime redeposited on the coin but it was fixed with another application and more work

[WoodenJefferson]

Until you have actually attempted to clean a coin with PVC residue, it's not just a simple dip and your done. It takes diligence and patients as Jason has pointed out.

 

It never ceases to amaze me that most soft "coin flips" can be and are dangerous to your coins over a period of time and that collectors, dealers and grading services still fervently utilize them to this day.

 

Thank you for sharing this informative series of "How to..."

[jgrinz]

THis whole Series should be moved to WHAT YOU NEED TO KNOW in my opinion and a well presented series - Great Job

 

[HCumberdale]

This really is great information and is 100% accurate. As an avid user of acetone myself I can personally corroborate everything in this post. Don't forget that once you are finished with the coin, give it a bath in distilled water for a few minutes. Fish it out and let it air dry on a paper towel before putting it back in whatever holder you want. Make sure to give the coin significant time to air dry, water can hide in the tiny details.

[Oldtrader3]

The flips that have damaged several of my more modern coins were bought from PCGS for use in submissions. For some obscure reason, I thought that they would not sell PVC flips to people who use them to submit coins for grading. Boy, was I wrong!

 

Now I have Mylar flips and the PVC ones are long gone.

[Mokiechan]

Great stuff, thanks for sharing.

[bsshog40]

Great "How To" series Jason!!!

[messydesk]

I've used a small jar (e.g., baby food, artichoke hearts, pimentos) with a lid. Put the coin on a piece of paper towel or rag in the bottom of the jar so it doesn't scrape on the glass if you bump it. With the lid closed, you can soak it for a while without the acetone evaporating.

[e1cnr]

good info

 

for Q-tips make sure you do not have plastic shaft, as they melt

 

wood cotton tipped applicators can be purchased that have a longer handle and work great.

[physics-fan3.14]

Glad y'all liked the series!

[No+4Me]

Aside from its use removing PVC, can acetone be used to remove "haze" from proof coins?

[physics-fan3.14]

Aside from its use removing PVC, can acetone be used to remove "haze" from proof coins?

 

I have not personally tried this, because I don't buy many proof coins. If the haze is organic in nature, then yes, acetone would work. However, I would use extra caution because of the delicate nature of the surfaces. Try it out on a common modern first.

[mtnstyne]

Jason, great info as usual and it was good to read again. I wonder, do you have any befor and after pictures of coins you cleaned that may have toning to them and any effect it may have had?

 

Ever since reading your series a couple years ago I have rinsed all my coins in acetone and then distilled water before putting into storage in a dansco or just in a the lock box. I have obstained however from doing this with toned coins because I am leary about the effects.

[delta]

While I gave an unqualified approval to the first two parts of this report, I regret I'm not fully satisfied with this last installment, and have the following comments and questions:

 

1. During coin soaking, acetone containers should always be very tightly covered to reduce evaporation, to reduce any chance of contaminants entering, to minimize the inhalation of the volatile fumes, and to reduce risk of accidental ignition. Why not advise finding and using proper containers with tight-fitting lids?

 

2. Most q-tips available nowadays are made with plastic shafts, and these will begin to dissolve in the acetone, and should not be used at all. Furthermore, I'd completely advise against rubbing with a q-tip for at least proof and unc coins, because of the possibility of making tiny hairlines, right?

 

3. Using your fingers for placing and removing coins in acetone is inadvisable. Of course the concentrated acetone is going to damage your skin. Of course some of it will be absorbed and enter your bloodstream. Why take the risk it will damage your health in some way, such as by reacting with some other substance in your bloodstream, and affecting your liver or kidneys? Furthermore, why introduce the oils and dead outer skin cells from your fingers into the coin soaking mix? Instead why not use the proper type of glove or forceps or some other method?

 

4. Why make a final rinse in distilled water? What's the rationale for doing that? I'm not convinced it's a necessary step, please explain in detail.

[johnny9434]

good information, thanks all

[physics-fan3.14]

While I gave an unqualified approval to the first two parts of this report, I regret I'm not fully satisfied with this last installment, and have the following comments and questions:

 

1. During coin soaking, acetone containers should always be very tightly covered to reduce evaporation, to reduce any chance of contaminants entering, to minimize the inhalation of the volatile fumes, and to reduce risk of accidental ignition. Why not advise finding and using proper containers with tight-fitting lids?

 

2. Most q-tips available nowadays are made with plastic shafts, and these will begin to dissolve in the acetone, and should not be used at all. Furthermore, I'd completely advise against rubbing with a q-tip for at least proof and unc coins, because of the possibility of making tiny hairlines, right?

 

3. Using your fingers for placing and removing coins in acetone is inadvisable. Of course the concentrated acetone is going to damage your skin. Of course some of it will be absorbed and enter your bloodstream. Why take the risk it will damage your health in some way, such as by reacting with some other substance in your bloodstream, and affecting your liver or kidneys? Furthermore, why introduce the oils and dead outer skin cells from your fingers into the coin soaking mix? Instead why not use the proper type of glove or forceps or some other method?

 

4. Why make a final rinse in distilled water? What's the rationale for doing that? I'm not convinced it's a necessary step, please explain in detail.

 

I will address your comments:

 

1. If you operate in a well ventilated space, inhalation of fumes is not a major concern. A few dust particles entering is not a big deal, and most coins don't require an extended soak - a few minutes is all they need. The coin I used in the thread took a long time, and I covered it with plastic wrap. This worked perfectly fine. You don't need to find a tightly covered lid - which is almost always going to be plastic anyways, and I wouldn't want to take the chance of damaging that.

 

2. I agree, only the original Q-tip brand Q-tips should be used. The shaft on these is cardboard, and thus immune to acetone. I thought I made this distinction, but may have neglected it (nevertheless, it is common sense not to use plastic in acetone). As for use on proof or Unc coins - go ahead! A properly applied Q-tip with acetone on it, lightly and gently used to conserve the surfaces will not damage even proof surfaces. I use it all the time on UNC coins, and have used it on proof. If you doubt this, perform experiments for yourself on low-value coins. I purposely bought a proof Kennedy for a dollar to test this out, and it left no marks.

 

3. The amount of acetone introduced into your system by using fingers in acetone is negligible, and has zero health side effects. I am not concerned, and have no hesitation to recommend this. I wouldn't drink it, but there is no reason to prevent skin contact. If you wash your hands before doing this, there will not be a major concern with introducing contaminants. What type of gloves would you recommend? Cotton would be bulky and not do anything, rubber and latex would dissolve. I suppose you could use forceps - but I would only ever use plastic coated tongs on coins to prevent the metal tongs from damaging coins. Obviously, plastic tongs are not recommended for this application. And thus, I recommend using clean fingers - it is the safest, least damage, cheapest alternative.

 

4. Make a final rinse in distilled water just in case there are any contaminants that redeposited, to remove all traces of acetone, and in case any fibers from the Q-tip were deposited. Is this step really necessary? No, you can do without it. But why take a chance? It doesn't hurt anything to put some water on a coin, and it ensures a good clean surface.

[delta]

Hi Physics-Fan3.14, Thanks for the detailed reply. I'm still doubtful about several issues:

1. If you have containers with tight-fitting glass lids, why wouldn't you prefer to use those? Why not try to minimize the acetone in the air around you? And when covering, why would you use plastic wrap instead of glass? Messydesk already recommended closed jars in a post above.

2. In my previous comment, I should have credited e1cnr for pointing out "wood cotton tipped applicators can be purchased that have a longer handle and work great."

3. Some coin tongs are made from a type of plastic impervious to acetone. Also there are gloves specially made for use with acetone. And there are other alternatives to dipping your fingers into it.

4. Why not make a final rinse in clean acetone instead of distilled water? One advantage of doing that is the acetone will evaporate in a few seconds, but you have to wait quite a while for the water, and while your coins are sitting out there waiting to dry, maybe picking up dust particles and microorganisms, you are also waiting. Isn't it much easier to let evaporation remove all traces of acetone than all traces of water?

[Hard Times]

Very nice Jason, thanks. There are also wood shafted q-tips of a variety of types, these can hold up abit better than cardboard shafted q-tips if there are repeated soaks of the shafts in fluid.

 

I have used acetone in a closed jar to aid in removing lacquer from coins. I let the specimen soak for weeks to months, it does not remove it, but softens it up and begins to disassociate it from the surface of the coin which can then be removed using a non-abrasive poker such as the end of a wooden stick, thorn or q-tip.

 

Acetone is completely inert to toning - at least toning that is the result of the conversion of Ag or Cu metal to oxides or sulfides thereof. Good for aiding of the remove of non-bonded material such as dirt, pvc, organic films, etc. as Jason has documented. I now make sure that any coins I send in for grading that are not bought and submitted directly at a show, get an acetone wash prior to submission, to insure what goes in the slab does not have unseen organic films (i.e. fingerprints that come out over time) so there are no surprises in a few years.

 

Best, HT

[physics-fan3.14]

Delta - glass lidded jars would work just fine. I personally don't have any. I would much rather use plastic wrap than a plastic lid because I can buy it in rolls of 500 sq ft for a couple of dollars.

 

As for #3, I have never heard of plastic impervious to acetone. I would be skeptical until I tried it. I really don't see the need for buying special equipment for this, as my fingers work just fine. However, if you want to, then go ahead.