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Pillar of the Community
United States
3234 Posts |
I recently showed some of my Canadian cents on this forum. A few of them had some green verdigris (corrosive) showing on the surface. You'll note in the AFTER pictures, that any green is largely gone from all those nooks and crannies. The 1925 still has a little bit showing. So, how did I do it? Just like I mentioned in a previous thread about these coins and as I noted in previous recommendation for treating dirt, et al on coins...Denatured Alcohol! I did an initial bath of about 2 hours. That was wildly unsuccessful. In fact, I was thinking I would be doomed to leaving the coins in olive oil for a year hoping that that stuff would do the trick. However, 24 hours later, the alcohol did the trick...well, not all the way. After the bath, you'll likely need to use a cotton swab like I did and use a little bit of pressure on the affected areas. About 90% of that green stuff came off. The stuff around the "N" on the 1925 needed a bit more "encouragement". I took out the clippers....yes....those sharp metal things...and....clipped off a rose thorn from in front of my house. The thorn, being organic material, if used without a lot of force, should not damage the surface of a coin. I used it around the "N" and the maple leaf. It turns out there's still some stubborn green stuff left, so the coin went back into the bath. If I'm unsuccessful tomorrow with this final bath, I'll likely just leave the coin as is. It looks pretty minor and really needs power to see that there's anything still on the coin. Some of you might ask...how do you prevent the green, corrosive stuff from coming back? Good question. I don't know if it can be prevented...on any coin...even one that hasn't seen any before. Perhaps these coins will be more susceptible now. However, if you keep the coins in a low humidity area, chances are you probably shouldn't see it come back, especially if you cleansed the coin well. You should use distilled water and/or pure acetone and pat dry. I really like the denatured alcohol cleaning solution for coins like this. I will use it first and foremost before going to acetone again. Here are the BEFORE pictures:   Here are the AFTER pictures of the coins cleaned/conserved:   ***Edited by Forum Dad to stack images and unstretch page***Edited by Prethen
07/11/2007 11:36 am
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Pillar of the Community
United States
2443 Posts |
It looks like most of the green was taken off except around a few of the leafs. Maybe you should try acetone?
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Pillar of the Community
 United States
3234 Posts |
I have found that acetone is really only meant to work on stuff like PVC and only when it's more on the surface and not really "attached" to the metal. The alcohol can also work on PVC but is also great on working under verdigris like this. Olive oil might be even more effective but I'd rather not have to wait 1 year.
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Bedrock of the Community
United States
20753 Posts |
I think you missed the point about cleaning coins. What you did is not successful at all. Anyone can remove contaminations on coins. Anyone can make them pretty and shinny again. The problem is they are now basically junk coins. When you clean a coin there is a great chance you removed some of the original material of the coin. If you've ever watched a program like the Antique Roadshow they explain that you ruin anything by cleaning, polishing, sanding, painting, etc. With wood furniture, for example, sanding removes some of the original material. Same with coins only as you remove any of the contaminates, so goes the metal. You may as well have used battery acid. That is the best way to make a Copper coin shinny and pretty and also, worthless. There are many, many products on the market to make coins look like new. Why not just use Tarn-X?
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Pillar of the Community
United States
3234 Posts |
Amazon99: You inspired me...I didn't notice those areas you referred to on the 1923...now they've been taken care of.  |
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Pillar of the Community
United States
3234 Posts |
Just Carl: Yes...if I took a brillo pad to it or used Tarn-X, you're absolutely right...the coins are junk. As they stand now, no one would be able to tell anything was done to them! Hence, the reason while this cleaning was appropriate and successful. I removed something from the coin that could cause future damage and limited the eye appeal.
It seems that you are confusing improper cleaning with proper cleaning techniques when applied correctly actually improve a coin technically and market-wise without hurting any layer of metal on the coin.
Tell you what...please...I beg you...send me all you "junk coins" that look like this that you know have been properly cleaned. And, guess what...they'll be a line of people, collectors and dealers alike who'll take those coins if I don't.
I suppose you don't know that denatured alcohol or pure acetone have no malevolent properties with coins. Yeah, I've heard stories of coins turning colors, but I believe it's exaggeration and bunk. If you used acetone on a coin and it changed colors, it's because you removed a layer of carp that hid what was really underneath. That's something that DOES actually happen!
You cannot honestly tell me, that you see any adverse affects at what was done. The coins have been visibly improved and protected now.
Edited by Prethen
07/09/2007 7:53 pm
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Bedrock of the Community
United States
20753 Posts |
True they are now a little prettier. However, if your near a coin show take them there and see what professionals tell you about your now cleaned coins. True if your not interested in value, keep on cleaning. Being a coin collector for well over 60 years I would never buy a cleaned coin nor accept one for more than using in a gum ball machine or giving to some kids.
As to Alcohol, not ALCHOLOL, and Acetone, I've heard of them. Degrees in Chem and Electrical.
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Pillar of the Community
United States
3234 Posts |
Thanks for pointing out the spelling mistake, Carl...taken care of.
I guarantee you, in the 60 years of buying coins, you've bought a fairly large number of "cleaned" coins whether you thought so or not. We all have and still do. If a coin is properly conserved and metal is not moved, it can be a very good thing. Although, I don't like buying circulated "white" coins. That simply looks unnatural and the coins have likely been chemically cleaned (or stripped); something that alcohol nor acetone could do.
As far as the coins being "prettier"...I wouldn't say that, especially if you think they're somehow "shinier"....again, metal was not moved nor removed nor was any luster affected. The coins are definitely more eye appealing now due to the missing crud.
Edited by Prethen
07/09/2007 8:26 pm
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Pillar of the Community
United States
2443 Posts |
Sweet I'm an inspiration, lol. I can't see any of the green at all on the coin, nice job. Just Carl, I don't think he's damaging the coin at all, like he said, he's not using a Brillo pad on it. I think this is more of an example of coin conversation rather than cleaning since no damage is being done to the coin.
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Pillar of the Community
United States
914 Posts |
Fantastic job Prethen!! I'll have to run to Home Depot and look for denatured alcohol now!! :D
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Pillar of the Community
United States
2177 Posts |
The after coins have dulled in appearance and because of that I wont be using that for my coins. And how about in the long term? I'd rather play it safe and not risk it.
Also I believe alcohol will suck up and dry any moisture. I believe it will only damage the coin further and the dryness may even cause it to corrode due to becoming brittle. Just my opinion. I could be way off base.
Edited by thingee
07/10/2007 12:26 am
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Pillar of the Community
United States
3234 Posts |
Thingee: I can see you might think the coins have dulled in appearance. They haven't. What you're probably noticing is a different level of brightness of the scan. The scans come off rather dark and I have to raise the brightness 20% to adjust to a more realistic view of the coin.
Alcohol will not dull the appearance of a coin, it will only remove the crud if it can be removed. Unless there are contaminants in the alcohol (hence the reason you need pure alcohol/acetone from a hardware store) there should be no long term effects. These solvents dry almost immediately upon hitting the air. Also, the coins should go through a final process of being rinsed off in distilled water and patted dry.
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Valued Member
United States
394 Posts |
Hello Prethen,
The coins look O.K. in a photo, but what do they look like with a loupe?
I hope that they still look O.K., but doubt it. Let us know, maybe we
are losing out on something. I have the same thoughts like Just Carl.
Berry
I must add a postscript for the Newbies, if you have to try Prethen's method, nothing wrong with that, but use coins that are relatively worthless and be sure to look at them under a glass when you are done.
I love the word "patina" which will be destroyed by his method, I believe. However, have a go and see what you come up with. If you are unsure of the results, go to a coin shop and get an opinion. Be sure to use a glass at the end.
Edited by Berry
07/10/2007 08:39 am
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Pillar of the Community
United States
3234 Posts |
Berry....no patina was lost...at all. The coins have the same surface look (minus green stuff) that you see in the photos. Under a loop....Well, lets just say, some of the green remnants that were detectable under a 10X loop were removed...the surface is unharmed. No hairlines were added; no damage was done....PERIOD I realize there are some cynical folk out there. Yes, using baking soda paste will totally damage these coins. Using water or a pure solvent will not damage a coin any more than it has already been damaged (such as removing dirt to uncover a problem).
If this was a Proof coin, I would say that anything making contact would like harm the mirrors. I would also be very careful about using much of anything or any pressure on an uncirculated coin as well.
I must say, that I don't wish to advocate everyone go out and clean all their expensive coins. I'm just saying, there's a right way to do it where coins that have little market potential can be brought back to market acceptibility if there hasn't been any irreversible damage already on the coin. Think about it...why do you think PCGS/NGC will bodybag a coin for PVC and (I've heard implicitly) suggest that if it were removed it would slab. These coins don't "turn" later on just because a proper technique of removing PVC was done!
Edited by Prethen
07/10/2007 08:50 am
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Pillar of the Community
United States
1173 Posts |
Prethen...thanks for sharing. Will be interested to see how the passage of time affects the conserved coins. There's little doubt that left uncared for, the verdigris would have completely destroyed the one for sure.
As you, or someone else said, it is likely that many, many coins have been carefully cleaned. If you are buying strictly uncirculated coins, you might avoid cleaned coins, but if you're collecting older circulated coins, that chances are that, even if the "skin" appears intact, many coins have been cleaned at some point in their long histories.
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Bedrock of the Community
United States
20753 Posts |
Just for clarification purposes. If you do try cleaning a coin with mormal store purchased items such as mentioned here, note the possible shelf life may effect your results. Here is a normal test. Use a clean glass dish. Place your Alcohol or Acetone on that dish. Allow to evaporate. If there is any residue, discard as contaminated. Note such solutions in cans can become contaminated due to long term storage in these types of containers. The insides of metalic cans are coated but eventually this coating can be disolved slightly by the solutions in them. Most of the items discussed are purchased in the paint department of stores and the quality is not important for delicatee situations. We use only glass contained solutions for experimentations in our labratories.
As to the removal of the green stuff on any Copper coin, it will leave a noticable mark due to the green STUFF was partially part of the metal of the coin.
In the vast majority of instances a greenish patina or coating on Copper is due to at first Oxydation of the metal. This is noted as Cu2O. Copper will not mormally combine with moisture but the Cu2O will now react with Carbon Dioxide (CO2) and Moisture (H OH) to form Copper Carbonate [CuCO3-Cu(OH)2]. This is the green stuff normally on Copper coins and if and when removed so goes part of the Copper. Note that in some areas, such as Indiana, where there is a large abundance of SO or SO2 in the air this will further mix with H OH to form an acid none as Surfuric or Sulfurous and further attact Copper coinage. Again as this is removed, so goes part of the coin.
Sorry about the H OH but moisture is actually a Hydrogen Hydroxide best called water.
If you go to coin shows you will always see people with 10X or greater magnification items for looking for just such cleaning.
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Replies: 50 / Views: 4,892 |
Posted 07/09/2007 7:34 pm
