To clean...or not to clean? That is the Question!

United Federation of Numismatic Chemists forming at Green18's house.

 

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Why my house? It's more convenient if we meet out by you Jim.

Warmer too........

 

Errer Collecktor?

 

But you have the scotch

 

You are only the 3rd person to notice that. Of course it is an error that I collect errors, I collect varieties

 

OK....Makes sense.

I got third? Better than my 'March Madness' selections where I dwell in the cellar.......that's OK though. There's wine down there........

 

"I drink a lot of whisky, It gives me such a glow, It makes me quite immoble, But it lets my feelings show."

 

English Penny, after cleaning.

I understand what little I do about chemistry from fifty years of practical experimentation, and a wee bit of reading.

One of the issues you raised (which types of contaminants) is good for some serious thought; how do you determine, as in the case of the reverse of this penny, what the goop is?

Water-clear, not yielding to a thumb-nail, apparently tough in the way that some adhesives can be once the solvent evaporates, which is to say solid, not even slightly gummy...but who knows otherwise without splashing something (hoped to prove innocuous) on the offending crud? I chose alcohol (denatured, ethyl) because I trust it most among all the others save perhaps mineral spirits and naphtha (Ronson lighter fluid). I go through maybe a quart of it a year, over half of that on the end of Q-Tips or dipped onto cotton make-up pads. If it fails, I move on to more aggressive aromatics; in this case such escalation was not necessary.

A one hour soak in DNA reduced the offending 'glue' to a clear jelly, which yielded to a thumbnail as easily as would ham-fat to gasoline. The 9.4 gram weight did not change.

A neat advantage to alcohol is it's solubility in water; a simple rinse in warm tap water and a pat dry on old cotton tee-shirt, and below you have the result.

Yeah, there's still stuff around some lettering on the obverse, and a few weird spots on the reverse...but the coin is otherwise in remarkably presentable condition, IMO.

So: the next cruddy coin will be chosen, photographed in all it's sordid filth...and another report filed.

Thanks for tuning in!

 

Removing dirt from coins - not cleaning

Altering toning - cleaning

 

Now THAT is what I call an obscure Buffett reference.

 

Wow, what an improvement

 

Scroungy 1943-S Walking Liberty Half



OK: The reverse has only the issue of red paint...apparently this was a 'bar-coin' at one time in it's long and varied life...and the paint will almost certainly yield to either liquid lye or acetone. Before that, however, ol' friend alcohol will be given an opportunity...perhaps after Simple Green. Obverse is an unknown crud (adhesive?) with color; as before nearly flint-hard. Something about it looks organic, so that makes me lean toward a water-based solution...maybe the SG will be the first approach.

I'll remind all of you that no bristles will be used, nor any other mechanical help more drastic than a Q-Tip.

More as it happens...

 

if the DNA worked on the Penny then I assume the residue was from a glue. But if that's the case I think many solvents would have worked as well. I am with Doug here, just get the xylene and use it first, or after water. If the DNA worked I am pretty sure xylene would have worked as well, but the xylene will also work on lots of additional organic compounds.

I would really avoid products like simple green as you do not know what has been added. I am all for experimenting, but I would think starting with water and than moving to xylol would be a much better first step.

 

OK: A warm water soak, dry, then xylene. I don't have any, so it's tomorrow.

Wikipedia says xylene is practically insoluble in water.

We shall see what happens...thanks!

 

To hear is to obey, Sahib. Thank you.

And now I've got the straight scoop! Very well done, and sincere thanks for your exhaustive efforts! That was refreshing, informative, and comforting.

I will add these wee details: NYLON tweezers won't mar your coins and are impervious to acetone...avail widely, I would think...buy virgin nylon; they may cost a bit more, but will repay your expense.

Also, Stainless Steel or (if you can find them) Stellite tweezers, with Teflon tip cushions. Look in Chemical supply houses, etc...even (sorry) feeBay.

 

Excellent, inexpensive, Nylon-tipped SS tweezers





Somewhere in this thread I spoke of these as an ideal, but hadn't bought them yet.

They arrived today, and are perfectly suited to the task of handling without damaging coins and other small objects in water, acetone, xylol, etc.

Two tweezers and freight from MA was $21.85; the tweezers are $6.95 each; freight $7.95.

Made by EUROTOOL, sold by National Jewelers Supplies, 101 Mystic Ave., Medford, MA 02155, 888-657-8665 Toll-Free.

I found them on eBay; beautifully made (no sharp edges, well finished rivets, serrated tips), they'll last my lifetime.

Please consider this a recommendation.

 

After reading posts, I find nobody really stated how to clean safely any old coins.?

 

Wow, resurrected a 10 year old thread. This is discussed alot, I'm no expert but I have dabbled and read alot.

To answer your question, the only 3 confirmed safe things to use on a coin are: Distilled Water, Acetone, and Xylene. Some say acetone can do weird things to copper coins. There is a product out there for cleaning/conserving copper coins and the verdigris they often develop though I can't recall the name.