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 Replies: 60 / Views: 7,938 |
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New Member
United States
20 Posts |
I have been dipping a coin in acetone before putting it in an Air-Tite. But I noticed that after putting it in acetone it always leaves behind some kind of stain. These stains are only noticeable when you scan the coin and zoom in. Dipping it for longer and then rinsing it with distilled water doesn't get rid of the stains. Using fresh clean acetone also doesn't help. I always wear powder-free nitrile gloves. I was able to get rid of the stains by dipping a q-tip in acetone and pressing the q-tip on the stain for a few seconds for all the stain spots. The problem is that after I get rid of all the largest stains more smaller stains keep showing up around the edge of the coin immediately afterwards. I have dipped this coin in acetone multiple times and have used a q-tip on it multiple times but I can never get rid of the stains or hazy spots on the coin. I scan the coin and zoom in and I always see a new stain somewhere on the edge of the coin after getting rid of the old stain. Does anyone have a solution? I circled the stains in red. I was able to get rid of those stains with a q-tip and acetone but more stains keep popping up (especially around the edge).  You can see on the right side where the word "GOLD" is that the background is hazy and a dull color caused by the stain. This stain is difficult to notice because it is not concentrated in one spot like all the other stains I circled in red.  |
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Valued Member
United States
221 Posts |
The gloves are one possible culprit. You might want to ditch using them that way. As PPE, thin nitrile isn't a good pairing with acetone, and I have seen some brands of powder free nitrile gloves leave residue behind on lab glassware. I use plastic locking forceps that are made out of an acetone resistant plastic (like polypropylene). You can probably find such tongs in a coin supply catalog. Test their solvent resistance first. I once purchased some tweezers that dissolved in acetone readily. I suspect they were polystyrene which is very soluble in acetone.
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Rest in Peace
United States
18456 Posts |
Yes don't use gloves at all . I have a unique way of picking my coins up out of the Acetone bowl . I use a pair of wooden chop sticks with a small piece of cardboard in between them on one end , then wrap that end tight with a rubber band . Use it like regular chop sticks but they will never fall fall out of your hands . Also you grab the coin around the rim , never touching the face of the coin .   |
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Moderator
 United States
187702 Posts |
Are you doing a final flowing rinse (not a dip) with fresh acetone and allowing it to air dry?
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Pillar of the Community
 United States
5662 Posts |
I agree it's likely the gloves. Nitrile gloves can dissolve in acetone, and that's probably the residue you're seeing.
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Bedrock of the Community
United States
94367 Posts |
Huh - using chopsticks to pick up coins. Why didn't I think of that?  |
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Pillar of the Community
United States
4691 Posts |
Debris will re-deposit if the acetone is not rinsed while the coin is still wet, preferably with distilled water.
Edited by jimbucks
08/31/2021 11:34 am
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Bedrock of the Community
United States
17884 Posts |
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Debris will re-deposit if the acetone is not rinsed while the coin is still wet, preferably with distilled water. I prefer a flowing rinse with fresh acetone. |
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Pillar of the Community
United States
3639 Posts |
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Huh - using chopsticks to pick up coins. Why didn't I think of that? Well, in my case that would definitely be a risky proposition! I know that when eating Chinese food, my chopstick prowess (or lack thereof) helps me stick with my diet as much of the food never makes it to my mouth...  Member of SPMC, FCCB, ANA and ANS. My U.S. Classic Commemorative Complete Set: https://www.NGCcoin.com/registry/co...sets/278741/My U.S. Fractional Note Set: https://notes.www.collectors-societ...eSetID=34188 |
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Pillar of the Community
United States
4680 Posts |
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I know that when eating Chinese food, my chopstick prowess (or lack thereof) helps me stick with my diet as much of the food never makes it to my mouth...  you and me both! @TBop.. you sure you're Italian? Do you use those chopstick for your spaghetti too?!?! On the subject, I'll echo what everyone has said about not using gloves. I use a good number of solvents in my profession and use a lot of nitrile gloves but never touch my "work" with gloves that have come into contact with a handful of solvents used. Acetone, lacquer thinner, and xylene/xylol being the 3 big ones. On coins that acetone leaves behind those hazy white spots or cloudy areas, I'll follow up with xylene. Start with just a quick bath. If this doesn't receive them then I roll over the area with a qtip. That said, I NEVER use a qtip on any thing proof due to scratching the mirrored fields. Also, I'm not a good collector so I cannot attest to the use of xylene on gold, maybe others can chime in there. |
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Bedrock of the Community
United States
20753 Posts |
1. Make sure your Acetone is pure. You can do this by placing some on a clean, clear dish and allowing it to evaporate.
2. After that if there is any residue, it is possible your
acetone is contaminated.
3. Also you might try rinsing the coin in distilled water after the Acetone. Then new Acetone rinse.
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Moderator
United States
187702 Posts |
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preferably with distilled water. No!  Quote:
I prefer a flowing rinse with fresh acetone. Yes.  Quote:
After that if there is any residue, it is possible your
acetone is contaminated. Yes. Always good to test your acetone. Pour some into a clean dish, let it evaporate, and check for residue. |
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Pillar of the Community
United States
5662 Posts |
A good test would be to pour some acetone into 2 clear glass dishes, then swirl your nitrile glove in one of them and let them both evaporate. That should give you the answer. I just handle coins in acetone with bare fingers--it will dry out the skin, but a brief exposure is relatively harmless. Chopsticks are good, too!
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Rest in Peace
United States
18456 Posts |
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@TBop.. you sure you're Italian? Do you use those chopstick for your spaghetti too?!?! Hmm ,thank you for mentioning that , I was only using them for my soup .  |
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New Member
 United States
20 Posts |
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Yes don't use gloves at all . I have a unique way of picking my coins up out of the Acetone bowl . I use a pair of wooden chop sticks with a small piece of cardboard in between them on one end , then wrap that end tight with a rubber band . Use it like regular chop sticks but they will never fall fall out of your hands . Also you grab the coin around the rim , never touching the face of the coin . Using chopsticks would be too risky for me. I drop coins sometimes even when using my fingers so chopsticks would be even worse. I always grab the coin around the rim even when I have gloves on. I just tried picking the coin up from the acetone using my fingers without gloves and new stains still seem to appear. Quote:
Are you doing a final flowing rinse (not a dip) with fresh acetone and allowing it to air dry? I just poured some acetone directly on the coin but the stains are still there. Quote:
1. Make sure your Acetone is pure. You can do this by placing some on a clean, clear dish and allowing it to evaporate.
2. After that if there is any residue, it is possible your
acetone is contaminated.
3. Also you might try rinsing the coin in distilled water after the Acetone. Then new Acetone rinse. My acetone is 100% pure. It evaporates very quickly. I don't think my acetone is contaminated I bought a new bottle and it still left stains like the old bottle. These stains are very tough. Rinsing definitely doesn't do anything. The only thing that works is a q-tip wet with acetone and pressing for a few seconds. But then new stains just appear in different areas immediately afterwards. |
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Rest in Peace
United States
18456 Posts |
It sounds to me that your coin or coins have stains on them before your acetone soaks . If so the acetone does not take away stains , only oil ,gum and containments . I don't know of anyone else having your kind of problems using Acetone . You are obviously doing something very wrong and hopefully we'll get to the bottom of this issue .  |
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Replies: 60 / Views: 7,938 |
Posted 08/31/2021 07:24 am
