Proper acetone procedure

By your numbers:

1. If you are not actively treating something visible/notable on the coin - like visible green or haziness from PVC - a couple hours is ample as long as you "swish" rinse after so nothing redeposits from your original soak. Even at that I'm probably - as is my way - displaying excessive paranoia. For a coin you've no reason to suspect, 10 minutes is probably sufficient. For efforts against visible stuff you would reasonably assume acetone to be effective against - that list is shorter than it might appear - well, the worst PVC infection I've ever treated took a total of more than a week (168 hours) of actual soaking time and a couple weeks altogether.

2. Use a bath of a type which will not allow the coin to lay flat. For me, that's various shotglasses keyed to the size of the coin. That way there's no question that both surfaces share the contact equally. It's also more conservative of acetone. I care not at all how much crud gets dissolved into a small amount of acetone because if it's that bad I'll probably use one or two extra soaks just to allay my fears of redepositing, after the coin looks fine visually.

 

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Good idea, for two reasons:

1) Less likely to break if you knock it down, splattering flammable acetone everywhere.

2) There's an ongoing debate here about whether acetone can damage copper coins. The paper that's usually cited by the "yes" side studied surfaces exposed to light; if there's anything to it, keeping your acetone in the dark while soaking things would help avoid the problem.

I'd be nervous about putting acetone in a plastic container. I know it's supposed to be compatible with polyethylene and polypropylene, but I'd still worry about it dragging out plasticizers that could react with your coin surfaces.

 

It's published scientific fact which can be duplicated by experimentation, just more difficult to do as an experimental numismatist because you have to arrange some....serious humidity. One could b0rk one's procedure sufficiently to duplicate it accidentally, but if you've that capability you probably shouldn't be handling acetone in the first place.

 

There is also a problem with peer review lacking. The paper is easy to find on the internet, but the research was seemingly backed by a company trying to show that using acetone to clean the end of copper pipes could induce corrosion before/after joining , whereas their product would not. Read it first if you have a physics or chemistry background before you decide. I have, and I am happily using acetone when needed, with no ill effects on the copper coins. Your Mileage may vary.

It is similar to the stories that Coke(tm) can dissolve your stomach or "meat" . and that is true if your "stomach" is a glass container unlike your real stomach which is coated with mucus and organics from its epitheium and is protected from the acid.
I suspect that the acetone story is appreciated by those who manufacture oil concoctions and such to clean copper and make that wonderful colorful toning
I own no interest in any products named or un-named here.

 

As I said: "ongoing debate".

 

It's pretty trivial to make copper the catalyst in a seriously exothermic oxidation of acetone (enough to make the preheated copper lose none of that temperature and stay red-hot), without the acetone actually igniting. That should be a hint even to the non-chemist (raises hand) of the potential relationship between copper and acetone.

And since the article we're both talking about publishes specific procedure, it's easy to duplicate itself with or without peer review. More here:

http://jes.ecsdl.org/content/147/11/4125.abstract

None of this makes me unwilling to use acetone on copper. Far from it. Conservation is about exacting procedure, and avoiding light when employing acetone/copper isn't difficult.

I'm going to specifically attempt to duplicate this myself during 2016, but I've a lot of pies in the oven at the moment so it's just another entry on the priority list.

 

If you have pvc drain pipes, don't dump acetone down the drain when you are done with it.

 

Unless, of course, you've decided to replace your city hookup with a septic field.

 

I just throw the small amount of left over acetone on my cement driveway and it's gone in seconds.

 

I thought acetone could get off verdigris, if it doesn't then how do I get it off one of my MS coins without damaging it?

 

If it's copper, use VerdiCare. You may or may not like the result, though, because if the verdigris is advanced enough, it may have eaten into the metal.

 

It's a high ms barber dime. i haven't done anything to it. I am not experienced, so would sending it to NCS work?

 

VC is effective on ALL metals, not just copper.

 

Thanks for updating us that you can use VC on all metals. I think many of us thought it was only for copper.

 

Examples:

 

A tiny speck, very very tiny. However if it will never grade.... Might as well get rid of it too. It's a nice dime. When I get the chance, I'll have to post a clear photo of it. It's a 1914 D Barber dime. I know I've posted up before, but I can't remember what forum it's in.

 

Thanks for that. Looks like it may straight grade. We'll see on the next submission.

 

I really appreciate all of the time and energy that you veterans put into helping educate us newcomers