I like Cleaned Coins and you should to thread

When i see very dark toning around the letters and deep parts of the devices I generally suspect a cleaning. Whether it is a harsh cleaning, i can not answer.

 

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It's not "What collectors have to do", it's "what collectors that are overly concerned about cleaning have to do".

The effects of circulation and effects of cleaning can sometimes be difficult to differentiate. They are difficult to differentiate because in some cases they basically do the same thing. You can look at a coin and observe it's present state, why does it really matter HOW it reached that state? If cleaning and circulation are difficult to differentiate, then why differentiate them?

 

Hello

When did the Moderators decide to make this a useful thread ...


Handy Candy Mandy

 

So I've tried a few more things to remove the gunk on my poor coin - 24 hours of acetone soaking, xylene, distilled water, boiling distilled water, and hot hydrogen peroxide - and the gunk remains stubborn as ever. :S Are there any glues that corrode copper? I'm wondering if the glue has corroded the copper and that's actually what I'm dealing with now. Because really, what kind of glue would NOT come off with everything I've done? :S

No clue how to handle corrosion without also damaging the coin, so now I'm considering NCS, but the price (between membership fees and actual conservation, not to mention insurance/shipping and the risk of loss involved there) and the "my coin got killed" thread make me wary. :S

 

Is it epoxy or glue?

 

My other hobby is carving wooden fishing lures. I use epoxy as the top-coat over the paint. Denatured alcohol works well for removing hardened epoxy, however, acetone usually works just as well. If it is epoxy, then soaking in acetone should have done the job.

Have you considered the freezing idea? Worth a shot, and will not damage the coin.

 

It could be epoxy for all I know. The person glued a draped bust large cent into a cardboard coin folder, I wouldn't put it past them. :S My first thought was superglue, but superglue should have come off in acetone.

Edit:

I actually did. I did alternating cycles of boiling and freezing in distilled water. Didn't work. Thanks though.
​

 

You can send it in to NCS through a local dealer to save on the membership fees. I'm shocked that nothing helped get that glue off.

 

OK, it's time to get aggressive with your gunk. Do you have any liquid nitrogen handy?!

 

There are no local dealers. D: I live in the country. The closest dealer is an hour and a half away, but I go to that town on a semi-regular basis so I could ask them if they could send it off.

Lol, I actually do, but I don't know that my bosses or advisor would approve of me using the liquid nitrogen to clean coins. There is a grocery store nearby that sells dry ice, though. Think that would work?

 

Heh, I'm not even sure what the effect would be. Liquid nitrogen is >100C colder than dry ice, so the effect would be more extreme. In the least, a deep freeze should make the material more brittle, and thus easier to chip off. Just make sure that you don't drop the coin after submerging in liquid nitrogen, at those temps metals become brittle as well.

 

Liquid Nitrogen would cause the coin to shatter.... i think

 

Hm, I dunno if I want to go that extreme yet (and I doubt I'd be allowed to use the school's liquid nitrogen for that purpose XD). Think I'll stick with dry ice for now, -78C is still way colder than my freezer.

Maybe if you dropped it? I've put a penny in liquid nitrogen before, and left it there for a while, the penny was fine. I didn't take it out and try dropping it/chipping stuff off of it, though. I also don't remember if it was a zinc penny or a copper penny, which may or may not make a difference.

 

I'm going to borrow your icon. This way I can get more Sympathy Maybe I'll have to draw a mustache on it though.

 

If it wasn't such a historical coin, I'd tell you to forget about it. That glue might well be bound into the metal and this might be beyound the expertise here on cointalk. This might take a professional restorer. In theory, all glue should be soluable in something. It might take a fine tool and a patience manual cleaning, and pray the metal doesn't discolor.

Ruben

 

I liked this from another thread so I'll repeat it here.


Originally Posted by kanga
Let's see if I can codify the "pants pocket/washing machine" method of cleaning coins.

First you have to decide HOW MUCH cleaning you want to do.
This is important in selecting from the following options.

OPTION 1 - Pants Type (chose one); only one coin per pocket.
1. Jeans - coarsest so best for the deepest cleaning (dirty jeans add a bit of fine grit for that little extra scrubbing).
2. Khaki Workpants - not as rough as jeans and not quite as gritty
3. Dress Pants, Washable - great for the "average circulated" modern coin
4. Dress Pants, Dry Clean - slightly softer touch than the washable pants but not recommended. The Dry Cleaner tends to keep the coins.
5. Sweat Pants - great for that light touch-up; may have to search for ones with pockets.
6. Silk Underwear - perfect for prepping a coin for submission to a TPG. Cleaning is so light that the TPGs won't mention it (even if they detect it). VERY difficult find ones with pockets.

OPTION 2 - Solvent
1. Hard Water - not recommended since it adds more crud than it removes.
2. Soft Water - best all-around
3. Alcohol - almost as good as Soft Water; helpful in removing oily residue. And if you select the right type (ethanol) you can drink it instead of throwing it away (don't try drinking methanol or isopropyl).
4. Acetone - great for the toughest crud. Tough to find the coin after the washing machine blows up and takes half the house with it. And the coin might not be recognizable when done. Test at a Laundromat first; look dumb when the police question you about what happened; point to someone else.

OPTION 3 - Additives
1. Nothing – if you are new to this cleaning method a good place to start.
2. Detergent – starts you well on your way to “blast white” silver and red copper.
3. Non-Chlorine Bleach – adds a slight twist when used with a Detergent
4. Chlorine Bleach – adds a big twist when used with a Detergent
5. Acids – requires a LOT of experimentation to achieve the desired results. Stick with the readily available types (hydrochloric, sulfuric, nitric), and toy with the strength. Aqua Regia is particularly good with gold. Again, experimentation should be conducted at the Laundromat; be prepared with various dumb expressions.

OPTION 4 – Drying
1. Only air drying should be used. Do NOT machine dry the coins. You wouldn’t want to alter the coin’s surfaces.

 

I have used a 20X lens and dental tools.

 

Haha, have fun. XD

So I tried a new thing. I've been trying to avoid chipping it off out of fear of scratching the coin, but I gave in and tried it today.



As you can see I got most of the thickest gunk off. The first image is the picture I posted earlier; the second is a picture I took today, after chipping it off with a beading needle (which is pretty soft). A lot of it came off quite easily, and was powdery, but as you can see there's still a lot that isn't coming off (or that I don't dare scrape off for fear of scratching the copper). Since it was powdery, and didn't really 'chip" off, I'm really thinking this is corrosion and that the glue has been removed. I mean, what kind of glue can resist boiling, peroxide, acetone and xylene? o_o

Since it's from glue, I have no idea what compound this corrosion is. I'm a biologist and a numismatist, not a chemist. Could superglue react with copper to form copper cyanide or some other copper compound?

And, since you guys haven't seen the obverse, here's a picture.