Acetone and spotting eagles.

Swampboy · February 3, 2007 9:02AM

Well I decided to give my Eagle an acetone bath. I was worried about milk spotting and it's probably
good I was. There was a rainbow effect to the left of the motto and I figured this must be the infamous residue the Mint can't be bothered cleaning of.

I followed robertpr's suggestions How to use Acetone and what it does.... .

After a soak of five and then twenty minutes in two fresh batches of acetone this is what I can see...

That rainbow residue disolved into two little spots you can see i n the light area.

I think I'll soak it over night and see what I have in the morning.

tmot99 · February 3, 2007 9:18AM

My first concern is the grade of acetone that you are using. Depending on the acetone, it could have small amounts of oils or other impurities that could leave spots or present other issues.

I personally use a hardware store grade acetone, but I'm typically not treating high MS or PR material with acetone.

robertpr · February 3, 2007 9:21AM

Are you saying the acetone caused the rainbow residue? If you were just trying to prevent spots, a quick dip should do. Or were you trying to remove the residue? Are you using the 100% pure acetone?

keets · February 3, 2007 9:24AM

you don't really need to soak that long in acetone unless what you're hoping to remove is heavy buildup. generally, a quick dip/rinse is all that's needed.

tjkillian · February 3, 2007 9:31AM

And make sure you are using 100% pure acetone, not some derivative of fingernail polish remover.

Use only in a very well ventilated room, it is dangerous and inflamable.

Swampboy · February 3, 2007 9:39AM

I went to two hardware stores looking for acetone.
When I didn't see the words pure or 100% on the label of either can I picked up the second can.
So I can't vouch it's 100% acetone.
The coin came with two little dark flecks one on Liberty's arm and one over her left breast.
I knew it only needed a dip to prevent spotting but I was trying to see if the acetone would have any effect on the dark spots.
After the initial five minutes the little rainbow effect was more prominent and the specks were smaller; that's when I put the piece back in for twenty minutes.

Thanks
-Gil

edit you bet I used it in a well ventilated area. Even so, half hour later I had a twitch in my eyebrow!!

robertpr · February 3, 2007 10:04AM

Yeah, if it's 100% pure it will say so somewhat prominantly on the container. I'm guessing it's not. That's OK, just be sure to rinse it well with distilled water afterward and the rainbow will likely go away.

MrSpud · February 3, 2007 10:14AM

Place a small amount of the acetone on a clean mirror (lay the mirror down horizintally, of course

)and let it evaoprate. If it dries with no visible residue it should be OK to use on coins. Not all 100% says 100% and even 100% sometimes accidently gets some residue dissolved in it sometime in its handling before it is packaged. If you can see any residue on the mirror, don't use the acetone because it will leave an unidentified residue on the coins. Distilled water will only take it off if the residue is water soluble, not if it is some wierd oily stuff or dissolved plastic.

Another thing to do is, right after removing the coin from the acetone, is to place the coin on a clean cotton cloth (an old shirt will do, has to be 100% cotton or it can dissolve. Polyester will dissolve in acetone and leave a sticky residue everywhere it touches) wait a second and then carefully turn it over and wait a few seconds for any remaining acetone to evaporate. Do this while wearing white cotton gloves and be careful to place the coin gently on the cotton cloth without any rubbing action that can hairline the coin. The cotton will wick off any excess acetone and further reduce the possibility of any residue being left on the coin.

I have no idea if rinsing a SAE in acetone will prevent the dreaded milkspots though.

DieClash · February 3, 2007 11:05AM

I use Koinsolv, which is a brand name solvent containing n-Propyl bromide, 2-Propanol, Dimethoxymethane, 2-Methyl-2-Propanol and 1,2 Epoxybutane.

This solvent is not Acetone but I understand that it has similar properties.

I usually just swirl the coin in a glass cointaining the liquid and then dip it in a separate glass as a rinse. Then let it air dry. Mostly I'm cleaning gunk off high grade circulated material and not Uncirculated or Proof coins.

Now that said, what ASEs are being treated for milk spots? Uncirculated or Proof? And does this treatement really prevent the dreaded milk spots?

BAJJERFAN · February 3, 2007 1:12PM

<< <i>Are you saying the acetone caused the rainbow residue? >>

Yes. If the acetone picks up oil/s from transfer lines, storage tanks, transport tanks, filling equipment it will leave that type of rainbow residue. Its possible that the cans that it comes in had oil residues in them before they were filled.

DubbleDee · February 4, 2007 2:16AM

You can pick up 100% acetone from Wal-Mart in the cosmetics section.

BAJJERFAN · February 4, 2007 2:23AM

<< <i>You can pick up 100% acetone from Wal-Mart in the cosmetics section. >>

But that is no guarantee that it doesn't have any other residues in it; it only means that it doesn't have anything else deliberately added to it. If you want really good stuff buy pesticide grade or HPLC grade from a chemical supply house if you have access to those sources. You might even visit your local pharmacy.

Acetone and spotting eagles.

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