Someone before you got it, yeah, might have fiddled with it. As you used acetone and handled it with care, you're not the reason it didn't grade.
Don't think I have ever seen Medical Grade acetone. I take it back, NF grade is National Formulary, which would be for medical use. In school, our acetone was usually Laboratory Grade which didn't have any additives. I think there is an Electronics Grade which would also be "pure". I would think if anything was added, it would be noted on the label. Can't really imagine drinking acetone...however, I've been told that drinking a few mL of diethyl ether (anesthetic ether) will get you drunk really fast...I've never tried it (although I've breathed a lot of ether).
Are there different grades of acetone and what are they used for? Technical Grade – Technical grade acetone contains the highest level of organic impurities. This does not make the acetone unusable, it is just not suitable for most consumer products, and personal care use. Industrial grade acetone is primarily used to clean and degrease metal machinery. Reagent/ACS Grade – Reagent or ACS grade acetone is much purer than a technical grade, being a minimum of 95% free of impurities. This grade of acetone can be used for a larger variety of products, and processes, but is not pure enough to be considered food grade. USP Grade – USP grade acetone is the purest grade of acetone, being 99.9% free of impurities and safe for medical and pharmaceutical use. USP alamo meets the requirements to be considered food grade, meaning that USP of food-grade acetone may be used as an indirect additive ingredient in various food packaging and production processes. Are there different grades of acetone, and where can they be found? There are three general grades of acetone purity; technical, reagent, and USP. These grades all serve different purposes and it is important to find the proper grade for your needs to comply with production or industry guidelines. Ecolink is a trusted bulk provider of chemicals and solvents that has years of knowledge and experience to help you find the best chemicals for your needs. If you need more information on the different grades of acetone or are in need of a knowledgeable bulk provider contact Ecolink today! https://ecolink.com/info/are-there-...ee general grades,technical, reagent, and USP.
Huh. What I remembered from my very old chemistry days was that Reagent was generally more pure than USP, at least for most chemicals. USP wasn't as strict about impurities that had no health impact, whereas Reagent limited all impurities, since different impurities could have an impact on different reactions. Spectroscopic grade tends to be even more pure, as I remember, and I guess there are higher and more specialized grades as well. Here's a description of seven common grades, with Reagent at the top. Here's a list that includes more specialized grades, mostly aimed at things I'll probably never get to do (high-precision analysis, biotech). From what I've seen, that grade is for semiconductor processing, where we're getting very close to doling out individual atoms. It's really, really, really overkill for coins, unless you're going to handle your coins only in positive-pressure clean rooms while wearing a bunny suit...
Jeff, You are correct. The trade name for the stuff is Bitrex. It’s touted as “the most bitter substance known to man” or something along those lines. Denatonium benzoate is also the denaturant in the government formula SDA-40B (Specially Denatured Alcohol, formula #40B). And yes, I can confirm that it is indeed VERY bitter.
In the sense you're thinking about - no, it does not. But that's because what you're thinking about is "harsh/improper cleaning" - not "cleaning". But in reality, yes, acetone absolutely counts as cleaning a coin. Ya see, when people talk about cleaning a coin, probably 98 out of a 100 times what they're really talking about is harshly and or improperly cleaning a coin. And that's bad, it's always bad. Cleaning, or proper cleaning if you prefer, on the other hand is almost always a good thing for it protects our coins by removing harmful or potentially harmful contaminants and or toning from the the coin. There are 4 basic and perfectly acceptable methods for properly cleaning a coin. All of them are good. 1 - distilled water 2 - acetone 3 - xylene 4 - coin dip As for harsh/improper cleaning, there are literally more ways than you can count ! And all of them are bad !
Unless you’re creating nanoparticles, Electronics grade of just about any chemical is overkill for just about every other application. The contaminants in Electronics Grade chem’s are measured in parts per billion(ppb). 1 ppb is 0.001 mg per kg. Most instruments cannot even detect to that level. Technical grade will PROBABLY work for any numismatic application, however to be safe, I’d stick with any of the other grades. USP/NF, FCC or ACS/Reagent grades will all work. Tech grade solvents will usually pass the purity tests for a food or pharma grade product, however they just don’t test them to such a degree. In addition, to keep the FCC (food grade) or USP/NF (pharma grades) designations, they must be stored and tracked differently from tech grade material, too.
I'd just strike out Xylene and go straight to the coin dip provided you knew what you were doing with it. A risk/benefit thing. The health and safety risks of fiddling with paint-stripper outweigh the zero-benefit you get from it in the vast majority of the applications. I don't use or recommend it anymore on coins.
To each his own I guess but xylene has its uses and it does remove things acetone and distilled water will not. And it's completely harmless to coins and harmless to you too with basic use. It is after all used by literally thousands and thousands of people on a daily basis, with no harm done to them.
Personally, I wouldn’t be too concerned about the brief exposure to either acetone or xylene. However, I do agree that skipping the xylene is still likely the way to go. Because even though xylene has a slightly broader solvency profile than acetone, they overlap sufficiently enough to eliminate the xylene.
Not always. And when it comes to copper xylene is pretty much always the better choice because sometimes, stress sometimes, acetone can react with copper and cause weird and unwanted colors on the coins. Xylene never does.
My experience in conservation is with silver coins. Regarding copper, I agree. Acetate-copper complexes (which can be generated when copper comes into contact with acetone) can get really “weird”. Xylene would be the better solvent choice when dealing with copper. I usually don’t do too much with copper, so it didn’t even come to mind. Thanks for pointing that out.
Yes, I think acetone does change copper a little. I never really noticed it until I heard it, and then paid more attention. Another thing I still stand by with acetone is it dulls toning, some, the more-noticeably, the more vibrant the toning. Very few agree with me on that, but I'm using distilled water when the toning is bright and flashy, and if it doesn't dislodge what I'm looking to dislodge, I'm thinking real seriously of letting the thing alone.
I follow the leaders and do not clean coins, unless they are ancients of course. Like they say, "At your own risk." Good luck.
Another cleaning coin thread in Coin Talk. I have been experimenting recently with ultrasonic cleaning and hydrogen peroxide. A small portable ultrasonic unit costs around $50. Add one cup of water and 4 tablespoons of hydrogen peroxide. My machine does 4 minute cleaning cycles. Test your local tap water on a new Lincoln Cent and determine if YOUR water hardness has any ill effects on the patina (i.e, copper over Zn core). Mine does not. If it does you must use distilled water. Period. I normally do ultrasonic cleaning first for well soiled coins below AU. Buy a camel brush and use this in the rinsing step. Once the loose particles are removed which may impose hairline scratches use your solvent of choice remembering they have little effect on removing copper oxides and no effect on silver oxide removal. Luckily I have a quantity of Freon TF saved from the early days. NOTHING cleans copper BETTER than Freon TF which USEPA has banned for many years. Study your soil removal task. If its metal oxide discoloration try ultrasonic cleaning then the camel brushing step afterwards. Clean only when necessary. Never clean Mint Red coins or Proof coins. You can try what I call the Tom Reynolds copper cleaning method. Immerse the copper coin in xylene minimally for a month. Use a toothpick to DISLODGE the particles in and around the coin's motif. Repeat as necessary. Some processes require 6 months to a year in a glass jar of xylene (xylem). Feel free to send me photos for my suggestions. OK ... you can continue now to talk in circles on what is better - acetone or xylene. LOL John Lorenzo Numismatist United States
