Cleaned coins vs Uncleaned coins

Does acetone leave a residue?...
https://chemistry.stackexchange.com...le-solvents-leave-a-residue-after-evaporating
Maybe wise to follow up with a bit distilled of soapy water.

 

Log in or Sign up to hide this ad.

delete

 

A pure solvent of any kind would not leave a residue. Now you might argue that a solvent that is 99.99% pure still has 0.01% impurity, but the impurity itself might be volatile. OTOH, "distilled of soapy water"...distilled water should not leave any residue while soapy water should be thoroughly rinsed or you have problems. Now, consider any surface impurities that your solvent has dissolved could still re-deposit as the solvent evaporates, one of the reasons I like to pat or blot coins dry.

 

Yes. That's what it's all about.
Whatever the solvent removed from the coin is still floating around in the solvent. The next bath in fresh solvent will reduce the impurities that can re-deposit. I always do at least three baths.

Just for fun, try this.
With each bath, put a drop of the used solvent on a piece of clean glass or mirror and let it dry. You can actually track the progress you are making with removing the impurities. It's not a bad idea to put a drop of the fresh solvent you are using on a piece of clean glass from the start. It's nice to know that the solvent you are using is not already a problem.

 

This made me think of using ammonia to clean glass in that it leaves no residue, I was curious and found this post...

I will now proceed to determine how effective ammonia is to remove toning... I have a problem.

 

You're confusing things. Cleaning glass isn't the same as removing metal oxides/sulfides, etc from the surface of a coin. And removing adhered organic contaminants using acetone or xylene is different as well. Better living through chemistry.

 

Toning

 

I would never use this on any coin.

 

Same here.

 

Ammonia will clean silver.

 

with acetone, I will soak the coin (and repeat) until all the pvc residue is gone, then rinse well under hot tap water, soak in distilled water and blot dry with a plain cotton towel. Haven't had any trouble with residue or spots.

 

The method I use to remove the red spots from my gold coins and the tarnish from my silver coins is the bicarb aluminium method. However, I would never use it on my numismatic or collectible coins.