Coin cleaning solutions

So if you have a copper coin that appears to have either lacquer or tape residue, soak in xylene in lieu of acetone? TIA

 

Log in or Sign up to hide this ad.

A super-saturated baking soda solution, then rinse thoroughly.

 

And don't drink blue gatorade while using it. Advice I gave Larry Briggs once.

 

Do you have any idea what a super saturated solution of anything is? I would recommend a dilute solution.

 

That's funny

 

One of my favorite demos...

 

Right. I guess I meant to say highly saturated.

 

Ouch! Didn't know that.

 

I don't see how it can be a highly saturated solution. My understanding is a solution is either:

- a diluted solution, or
- a saturated solution, or
- a super saturated solution

'Highly' saturated, to me, would cross the line to super saturated.

Please correct me if I'm mistaken here.

 

@GDJMSP, there's been some chatter throughout CT lately about the use of industrial acetone solutions for "cleaning" coins. This makes me curious if there's a certain grade of "acetone" that's deemed acceptable to use for collectible coins. (not that I am going in this direction now) Please take a look at this link: https://ecolink.com/info/are-there-different-grades-of-acetone/

Are there different grades of acetone and what are they used for?

• Technical Grade – Technical grade acetone contains the highest level of organic impurities. This does not make the acetone unusable, it is just not suitable for most consumer products, and personal care use. Industrial grade acetone is primarily used to clean and degrease metal machinery.

• Reagent/ACS Grade – Reagent or ACS grade acetone is much purer than a technical grade, being a minimum of 95% free of impurities. This grade of acetone can be used for a larger variety of products, and processes, but is not pure enough to be considered food grade.

• USP Grade – USP grade acetone is the purest grade of acetone, being 99.9% free of impurities and safe for medical and pharmaceutical use. USP alamo meets the requirements to be considered food grade, meaning that USP of food-grade acetone may be used as an indirect additive ingredient in various food packaging and production processes.

 

When you come right down to it, "degreasing metal" is exactly what we're discussing here.

I'd say technical acetone is probably usually fine, but part of the "technical" grade is that there's not particularly close control on what kind of impurities appear in each batch -- just that there's not supposed to be enough of anything to interfere with "normal use". Getting grease off metal is "normal use", but being super-fussy about the metal's color after cleaning probably isn't. (I wonder if this is how acetone got a reputation for changing the color of copper coins -- all you'd need is a technical batch that's a little high in acetic acid, and presto, pinkish copper.)

The part dismissing "Reagent/ACS Grade" in favor of "USP Grade" is essentially wrong. The Reagent grade is 99.5% pure, not 95% -- but the remaining impurities aren't guaranteed to be things that are safe for medical or food use.

For USP grade, it is guaranteed to be safe, not for drinking, but for (say) preparing food containers, or extracting flavor components. USP grade acetone happens to have a higher guaranteed purity than reagent grade, although I'm not sure that's true in general for other chemicals. I'm pretty sure that the additional purity makes no difference for use cleaning coins.

 

Your stomach has fairly concentrated sulfuric acid too...

 

For acetone, just don't use fingernail polish remover!

 

Hydrochloric, unless you're eating really wrong, I think.

 

I knew that. But I'm a tough one. It's just how the Big Horse In The Sky made me.

 

How is the "punchiness" coming along, Doug, from the years of xylene inhalation, is it any better? To wit, we should always caution on poor ventilation when using this. It's not like nail polish. Just getting your back, here, chief. The little brats just coming on and learning from us should thank me for this...

 

Oops, gotta change my diet

 

You are absolutely correct, using a couple of mL of acetone in the bathroom to quickly rinse a coin is not like soaking large numbers of coins in xylene in an enclosed space.