Question related to acetone cleaning

Hello,

I found a great post from Doug on using acetone to clean coins. Right now, I have 3 silver coins which are already 12 hours in acetone, and I will take them out in another 12 hours, rinse them two more times in clean acetone and I hope there will be some difference. There are some photos of each coins I took before putting them in acetone.

This some pvc residue on one coin, and for other coins, I could not find out what kind of residue is on them exactly. In the post I mentioned, it says that acetone is not very good for ordinary dirt and grime.

Would it be wise to first soak a coin in lets say distilled water (or 2 times distilled water) to try to remove the dirt and grime (of course, just dipping, without any kind of brushing or wiping) and then continue with acetone procedure? What about soapy bath (distilled water and just little bit of soap) instead distilled water only?

Is this procedure for silver coins only or should it be used on aluminium, stainless stell, zink etc. coins?

 

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Soap will dull the surface and freak out a discriminating eye. Toning of course being superficial, there are some who maintain it even flattens out any toning. Acetone will remove most glues, tapes, or of course nail polish, but that's about it. Use distilled water of course to remove dirt.

 

Should I then bath the coins in distilled water first, and go for acetone? This way, I should be able to clean (hopefully) both dirt and any glue, tape or pvc residue.

 

Sure. As a general rule of thumb, always do the least invasive first.

 

Thanks. Any idea how long should the coins stay in distilled water/acetone? Also, should I try this on zink, copper, aluminium coins as well?

 

Acetone cannot penetrate dirt. If you have PVC residue or the like and it is underneath dirt on the surface of the coin, guess what happens if you put the coin in acetone. Nothing. For dirty coins you have to soak in distilled water first, for this reason.

You work top down removing layers of contaminants. Dirt and grime, then adhesives and oils, then undesirable toning like cloudiness (if you are dipping).

 

Can you share his post? I am getting ready to practice on a few junk coins and would like to read it. Also, please share your results and soak times in water once you are done. Thanks

 

https://www.cointalk.com/threads/proper-acetone-procedure.193708/

The second post describes the procedure. I will share the results.

 

Try to show a before and after photo. Jim

 

I can't agree more.

 

Thanks! I just read all 15 pages. Going to try this on some coins with pvc growing, magic marker on them and some toned coins.

 

Anything acetone will do, it will do quickly. A couple of minutes or less. It will not remove PVC “residue,” which is not residue but corrosion.

PVC, by the way, does nothing to coins unless, in the form used for water pipes, it scratches them. The phthalates added to PVC to make it flexible are acidic, and they corrode the coin. They are also called endocrine disrupters that can cause birth defects and in some places are illegal to have in anything that contacts pregnant women or babies.

 

A short exposure (less than an hour) of more reactive metals like copper, zinc and aluminum to high-grade acetone is unlikely to hurt them. I recommend only reagent grade acetone be used. Impurities will be in higher concentration in lower grades of acetone. Concern with longer exposure is that some of the impurities sometimes found in acetone are phenol, formaldehyde, acetaldehyde, and acetic acid. These will attack reactive metals.

I recommend that coins that have had an acetone bath be rinsed with fresh acetone and allowed to air-dry rather than be rinsed with water, which may leave a coating or spots. Remember acetone and its vapor are extremely flammable. Do not reuse acetone.

Be aware that even a short exposure of copper coins to acetone can noticeably alter their appearance. This is because brown color that is assumed to be toning may be due in part to dark colored dirt, oil, wax, varnish, etc. These substances will be removed, and the coin color will be different after its acetone bath. The new color may or may not be an improvement.

If something is attached or applied to a coin (hologram, gem, artificial color, etc.), acetone may remove it.

Cal

 

So, this is the first result. I am really bad at taking photos as you can see, but next time it will be better. All of the three coins were dipped in acetone for around 24 hours. After that, they were rinsed 2 times in clean acetone and let dry. The first difference which probably can not be seen on photos is the stronger luster on all coins.

 

As others have said, acetone will remove many organic materials, but does not affect the toning/tarnish. The remaining discoloration on your coin may be related to environmental toning, so you may have gone as far as possible with acetone.

Also,the 2 Reichsmark coins in your pic have a .625 Silver, .375 Copper composition. As Doug mentioned above, the key is knowing the correct method to lightly clean the coin without damaging the surfaces. It could be a challenge to find the right method with that composition. I would recommend leaving your coins "as is" unless you have a lot of experience and/or practice on some of the less expensive 2 reichsmark from the later 30's rather than the Luther's.

 

Regarding coins and solvents...

Starting with water is always good. Distilled if you wish, but I like to run the water in a sink until it is HOT then let the hot water play over the coins for 15-60 seconds. After this, you can rinse in distilled (or deionized) water, but I always like to blot the coins dry. Afterwards, acetone or xylene or both. For silver a quick (< 1second) dip in eZest is pretty non-invasive.

 

I agree. As said before, my skills with photo taking are quite bad and I will try to improve that. Since it is hard to see any real change if the photos are just lighter overall.