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 Replies: 92 / Views: 20,711 |
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Pillar of the Community
 United States
1795 Posts |
BadThad I find you test very interesting and will use you methods when I do my testing. I will be more than glad to back up your findings Thad. Ty again.
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Bedrock of the Community
United States
19966 Posts |
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Thad, might I suggest standing a cent on edge so that you soak HALF of the coin in the acetone. Showing the whole coin before and after soaking opens questions of possible differences in photography or lighting etc and frankly the fact that you are looking at two different pictures makes comparison slightly more difficult. But a single coin that has been half soaked will show whether or not the color of the coin has changed. (I don't believe there will be any change.)
One problem you do still have is that even the mint red coins straight from a "mint" roll (or even one purchased directly from the mint.) will still have a layer of oil on them from the coining process. The press is lubricated, the dies are oiled even the planchets are oiled so they won't stick while moving through the feeding mechanisms. The removal of the oil layer could create a slight difference in the appearance. I thought about a half and half test but it's too difficult to stand the coin up in my bottle like that. Plus, acetone vapor will fill the air space and, while not soaking, it will be exposed to acetone vapor. There's a derth of information on the exact metalworking fluids and cleaners the mint uses. They seem to keep it a closely guarded secret. The only info I've been able to get was from a chemical supplier to the mint I know. He told me about a single component that led to the development of VERDI-CARE. I do know they make their own fluids in-house. I'd be very surprized if they are in fact using any type of petroleum oil based products these days. Almost all shops are using synthetic (water based) materials for metal operations for numerous reasons. I work for a company that produces metalworking fluids and >90% of our sales are from synthetic products. I'm 99% sure the mint performs a rinsing operation after coining to remove the lubricants and to add an anti-corrosion protective chemical to the coins. I believe that rinse is responsible for the spots we see on the majority of coins, especially cents. I may repeat the experiment with a chemically cleaned coin or two later. For now, you all will have to trust my eyes if the pictures don't show anything. Lincoln Cent Lover!VERDI-CARE™ INVENTOR https://verdi.care/
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Moderator
 United States
189340 Posts |
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Running the test....  |
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Bedrock of the Community
United States
20753 Posts |
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I thought about a half and half test but it's too difficult to stand the coin up in my bottle like that. Plus, acetone vapor will fill the air space and, while not soaking, it will be exposed to acetone vapor.
Just use a Copper glue on the bottom of the Glass to hold it in place.  Or hold it with your fingers. Or stand it up agaist the side of a glass. As to the air space above the Acetone, simply light it with a match to get rid of the vapors.  Weld a piece of Copper wire to the top of the coin and let it hang over the edge. Use only Copper brazing rods though. All is just sort of a waste of time. I've been using Acetone on Copper for so long and nothing, nothing ever happens. This subject comes up so often I really think we need a sticky called Acetone. Edited by just carl
09/18/2012 8:30 pm
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Pillar of the Community
United States
1795 Posts |
This is getting better and better, keep the input coming everyone. Ty All again.
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Pillar of the Community
United States
1757 Posts |
I guess when I say blue-ish it's not clear ... perhaps a slight blue impartment to the red mint tone is better said ... if you see no blue entering into the red mint state tone ... so be it ... no big deal ... my only feeling is that blue is not a natural oxidative state of copper ...
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Valued Member
United States
280 Posts |
Actually, copper salts cause the color blue in fireworks. Maybe a combo of different chemicals reacting could theoretically cause a slight blueish tinge...  However, I would not know for sure since I have never used acetone on copper as of yet. However, it did wonders in getting over 50 years worth of grime off of a silver quarter I got from circulation today . Simply dip a cotton ball in acetone and rub, it comes right off! I do not recommend high strength acetone since you do have to use your hands to hold and scrub. Good luck to everyone and their acetone adventures!  |
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Pillar of the Community
United States
1795 Posts |
Interesting thing about acetone...If you put it on your finger tips you will temporally loose your finger prints for a while. Learned that in welding class years ago. Weird but true. Not sure what it does but it does work.
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Bedrock of the Community
United States
20753 Posts |
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Actually, copper salts cause the color blue in fireworks. Maybe a combo of different chemicals reacting could theoretically cause a slight blueish tinge... Way back in college Chem classes we used to put Pennies in Sulfuric Acid. After the coins were completely melted, Distilled water was used to thin out the solution which is now dark Blue. Running it through filter paper and then allowing to slowly evaporate, almost clear blue crystals would be the residue. Copper Sulfate is Blue. However, can not imagine how Sulfuric Acid could get into this situation. |
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Valued Member
United States
337 Posts |
Now I'm wondering if some of the old coins could use a vinegar bath to help the dates/pictures come through more. Something to think about. Good thread!
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Valued Member
United States
71 Posts |
Err on the side of safety
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Moderator
United States
189340 Posts |
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Err on the side of safety Yup. If you have to ask how to use <insert chemical substance here> on a coin, then you should probably not use <insert chemical substance here> on a coin.  |
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Pillar of the Community
United States
1200 Posts |
I read this entire thread and finally got dizzy from all the input. I'm not a chem or bio degree-holder, but I do know that MSDS's aren't total jokes and that both acetone and MEK are known, proven carcinogens. I tread lightly around known carcinogens and I keep my distance from them. I think the input in the last two posts immediately before mine contain the advice I feel most comfortable following, and to me that advice translates as "Avoid acetone and MEK as if they were cancer."
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Moderator
United States
189340 Posts |
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...that both acetone and MEK are known, proven carcinogens. No, they are not. |
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Bedrock of the Community
United States
12437 Posts |
Acetone is definitely NOT a known, proven carcinogen. In fact, the human body actually produces acetone as a byproduct of metabolism. You are right that MSDSs aren't a total joke, just 75% of a joke Material Safety Data Sheets are written by pinhead lawyers with an eye towards every potential legal liability(real or imagined) in a commercial/industrial setting, they are useful but only to a point. Quote:
2. HAZARDS IDENTIFICATION
Potential Health Effects
Inhalation May be harmful if inhaled. May cause respiratory tract irritation.
Skin May be harmful if absorbed through skin. May cause skin irritation.
Eyes May cause eye irritation.
Ingestion May be harmful if swallowed.
4. FIRST AID MEASURES
If inhaled
If breathed in, move person into fresh air. If not breathing, give artificial respiration.
In case of skin contact
Wash off with soap and plenty of water.
In case of eye contact
Flush eyes with water as a precaution.
If swallowed
Never give anything by mouth to an unconscious person. Rinse mouth with water.
8. EXPOSURE CONTROLS/PERSONAL PROTECTION
Hand protection
Handle with gloves. Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.
11. TOXICOLOGICAL INFORMATION
Potential health effects
Inhalation May be harmful if inhaled. May cause respiratory tract irritation.
Ingestion May be harmful if swallowed.
Skin May be harmful if absorbed through skin. May cause skin irritation.
Eyes May cause eye irritation.
The preceding is an excerpt of an actual MSDS from Sigma-Aldrich, can you guess what scary and dangerous chemical it is for? Molecular Biology Reagent Water, nothing but one oxygen and two hydrogen atoms. My favorite is the bolded parts under First Aid Measures  Yes, this is probably the most ridiculous example I could find but it still proves the point that MSDSs are not the end all-be all of chemical safety. In many cases, simple common sense trumps the MSDS. |
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Posted 09/18/2012 2:39 pm
