Where to buy correct Acetone?

Does your microscope do spot chemical analysis?

If I ever [play the lottery and] win the lottery, a good XRF setup is high on the shopping list. And maybe an FTIR spectrometer. (Holy cow, a quick search made me think you can land the latter for under $1000! Turned out the displayed price was for a one-week rental. Sigh.)

 

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So you don't think one can identify typical coin contaminants well enough with optical magnification? Well enough to not waste time with a 4-solvent gauntlet, would be my guess.

 

For me, acetone and xylene have performed very similarly. Both are effective at removing the organic gunk that can accumulate on circulated coins, as well as adhesives. (I always treat uncirculated coins too, because I have no way of knowing how they've been stored nor what unseen contaminants might lurk on their surfaces).

At the risk of provoking another debate among the CT chemists (please don't, that's not what this is about), I would add that I've had a handful of unpleasant outcomes with acetone on brass plated* coins, aluminum* coins and, in one instance, a bronze coin (a 1940s British India 1/4 anna to be precise).

Could there have been other chemicals present on those coins that contributed to the aforementioned problems? Possibly, but it's been way too long since college chemistry for me to hypothesize, nor do I really care. Suffice to say, to play it safe, I use acetone on silver and cupro-nickel coins, and xylene on anything else. Since I started following this protocol I've had no issues and both solvents seem to get the job done.

*Pretty much a non-issue if you're not into world coins.

 

Use positive ventilation, or a fan when using. Or outside, with wind blowing away from you.

 

The key difference between acetone and xylene is the polarity.
Acetone is more polar than xylene. Acetone is compatible with water, whereas Xylene has very low polarity, and hates water.
This means acetone will remove stuff which is compatible with it. It is a good compromise solvent for a wide range of materials of mixed polarity.

However, acetone will not remove some very low polar deposits. For these you need xylene (or toluene, hexane, etc).

That is why the advice to start with acetone is a good one.
If no work, use xylene.
If that don't work. Stop, or continue at your own peril.

Use proper ventilation for all of these!

 

I used to use Kodak Film Cleaner to, umm, err, clean film of contaminants. That stuff had a heapin' helpin' of heptane.

Then there was the movie film version, also cleverly named Kodak Movie Film Cleaner with Lubricant, which had a (wait for it) lubricant specifically added to it.

Kodak's product names were cool that way. They had a chemical whose purpose was to tone the grays in a black & white print to blue. Yup, it was called Kodak Blue Toner. Think of what they saved on branding experts.

 

If you find a source of toluene, let me know. It was removed from general distribution a while back, probably because it was too tempting as an inhalant, and I guess it could be a meth precursor if you're ambitious.

If you find a source of hexane, run the other way. I'm usually the one protesting that solvents aren't really that dangerous, but hexane is BAD. As in "rot your nerves if you're chronically exposed". It's markedly worse than pentane or heptane, and probably a good bit worse than xylene. Certainly much worse than acetone.

 

You are absolutely correct to point our hexane should not be used.

I was using it as an example of a non-polar solvent. BUT, I should have been clearer that it should no be used.

(Toluene is available in Europe from various suppliers).

 

Seems to be available. I find listings for it from auto paint stores and some hardware stores under the name Klean Strip Toluene. the Safety data Sheet lists it as being 100% toluene.

Also found it from a chemical supply house but you have to have an account. Didn't check to see what it took to set up an account.

 

Huh. I last checked a couple of years ago, and it seemed like it had thoroughly disappeared. I'll try again. Maybe I was just put off because it had to be shipped, and hazmat charges made it uneconomic.

I work at a place that has business buying reagents. If I decide it's time to make the garage even scarier than it already is, maybe I'll see what they can do for me.

Edit: O'Reilly Auto claims that I can order it for delivery to a local store. Pricey (~$26/gal), but cheaper than hazmat shipping.

Walmart Marketplace will also sell me a 5-gallon pail of it for $120, "free shipping". No, thanks. Now that I'm paying for my own home insurance, there's a limit to how much flammable stuff I want under my roof.

 

Got an ACE Hardware near you? I checked several and they seem to have it for $20 a gallon. But you can't get it in California, they have banned it.

 

My corner hardware store is an ACE affiliate. I think they were True Value the last time I asked. I'll try again.

Sooner or later Californian voters will approve a proposition banning Californians, on the grounds that they contain materials known to cause cancer. Until then, I'll only visit occasionally.

 

Well I don't know about causing cancer, but I think we can definitely agree they are harmful to the environment.

 

I feel sorry for them for a few reasons, but envy them for others. Right now, on balance, I'm not tempted to move. They're probably just as happy for that.

 

As are we all.

For certain definitions of "harmful", at least...

 

I have used both acetone and xylene on silver coins. It can be used on gold (but I never have) and nickel. But NEVER on copper or brass, or bronze. I have had great sucess with both. But don't expect to it do miracles. I had a well circulated Walker that had some black spots on it (they sort of looked like paint). They all looked the same. Acetone got rid of some. Then I tried 24 hours in xylene which got rid of a couple others. But between the two dips there were still some spots. The down side was that with each spot that was removed left a bright sport. Oh well. But the treatment didn't touch any of the orginial circulated toning on the coin.

I get a lot of junk silver that often has 'who knows what' on them. Grease, grim, crude, whatever. The acetone does a great job of getting rid of that 'stuff' without effecting the coin or giving it any sort of 'cleaned' look.

 

Welp, my neighborhood Ace can order toluene for me -- $19.99 a gallon.

But I have to buy a case (four gallons).

But I get a 10% case discount.

I'm thinking about it. But I might make the side trip to O'Reilly's instead. Extra quantities of flammable solvents are a liability as well as an asset.