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Pillar of the Community
United States
2600 Posts |
First, I would give a ride on my new Harley Road King for a copy of your formula, Rick. Seems that I remember you in a pic with a Harley posted here on the forum. Thought maybe I could tempt you.  Regarding cleaning, I tend to agree that almost no coin should be cleaned, however, conservation done properly cannot be bad. In some instances though, cleaning becomes a last resort. I went to an auction a few months ago and bought a lot of copper large cents and other copper coins that were beyond recognition. Most were worn smooth. A couple had enough detail that they are in 2 x 2s and two of them looked like they had dried bubbles all over them. No detail was visible on either side, they were obvious metal detector finds. Before putting them in the jar for the nephews and nieces I decided to put them in olive oil first. Now, after about 4 months, they are both coming along nicely and I will post pics in about a month when I end the process. One of them is now 90% legible and is a 1864 Two Cent coin and the other is an 1829 Half Cent. It is simply amazing what olive oil has done for these coins. They have gone from being old discarded pieces of bubble gum to coins that I will be proud to show. Now tell me, how can cleaning off years of crude been wrong on these coins.I only wish I had taken before pics, but they were so bad I just never expected these kinds of results. Jim Hmmm, this thread got me thinking and I just checked the book. It would seem I need to go and see if the 1864 is a small motto. Darn it, Large Motto.  Edited by Jim1953
07/15/2007 9:44 pm
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Pillar of the Community
Czech Republic
803 Posts |
How do you guys feel about reversing the toning, using chemical reaction to convert the silver sulfide back into silver? I've tried this and it appears to be a non-damaging way to "brighten-up" or remove toning, depending on how dark it is. This does not remove any of the silver. It's based on the fact that aluminum reacts with silver sulfide (toning) and in this reaction, sulfur atoms are transferred from silver to aluminum, freeing the silver metal and forming aluminum sulfide.
It's easily done with some hot water, aluminum foil and baking soda.
Let me see if I can find some before and after pictures from my experiments...
~Roman
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Pillar of the Community
Czech Republic
803 Posts |
A-ha! Here's an 8 Reales piece from Lima, which is displaying some unusual characteristics. I wanted to see the damage, as well as surface characteristics under all that toning and used the above mentioned method to get the following results:   ~Roman |
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Pillar of the Community
United States
2600 Posts |
Two, tell me more about this. Jim  |
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Pillar of the Community
Czech Republic
803 Posts |
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Bedrock of the Community
United States
20753 Posts |
How do you guys feel about reversing the toning, using chemical reaction to convert the silver sulfide back into silver? I've tried this and it appears to be a non-damaging way to "brighten-up" or remove toning, depending on how dark it is. This does not remove any of the silver. It's based on the fact that aluminum reacts with silver sulfide (toning) and in this reaction, sulfur atoms are transferred from silver to aluminum, freeing the silver metal and forming aluminum sulfide.
It's easily done with some hot water, aluminum foil and baking soda.
Let me see if I can find some before and after pictures from my experiments...
~Roman
Your partially correct. However, that reaction does not replace the Silver in the same places it came from. It just deposits it back to the coin but anywhere at all. This process will naturally make the coin look shinny but as usual, it can be detected and would be considered cleaned. Any process that is used for cleaning can and is detectable be the grading services. As long as a person doesn't care about attempting to sell such coins, probably doesn't matter what you do with it. This is the same pricipal of completely modifying an antique to look pretty. For example you can take a few hundred year old chair and sand it down, put new varnish or paint on it, but it is now ruined as an antique. True it could still be sold for something, but the most massive value is gone.
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Pillar of the Community
Czech Republic
803 Posts |
Carl, at 20x I saw nothing additional deposited on the surface of the coin. The only thing pointed to this procedure were a couple microscopic blueish "burn" spots where aluminum was in contact with silver during this electrochemical reaction. In any case, it served my purpose and I simply suggested it as an alternative to dipping (if one feels necessary to do so in the first place).
Myself, I appreciate a nice, "crusty", coin for my primary collection. I use acetone to remove organic surface contaminants from all my silver coins. When I worked in IT a few years back, we used pure acetone to clean glass strands for fiber optics, which was proven to leave no residue after evaporating.
~Roman
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Pillar of the Community
United States
1173 Posts |
Antiques of all sorts that have been damaged in any of many ways can be and should be restored/conserved to prevent further deterioration and loss of value. Value, as a matter of fact, is often enhanced by the conservation/restoration efforts. Such activities are best undertaken by experts, and should focus on maintaining the fundamental integrity of the piece. Of course, buyers should be made aware of the conservation efforts.
The flag that inspired the Star Spangled Banner is currently being restored by the Smithsonian. I guess if it was a coin, we'd just let it corrode away to nothing and pat ourselves on the backs for our lack of effort.
I am NOT endorsing wholesale cleaning of coins...but coins that are being slowly but surely destroyed by corrosion are prime candidates for conservation. Maybe that is nothing more than sealing them in airtight holders if that is sufficient to prevent further corrosion. If something more drastic needs be done, so be it. If such coins are put on the market at some later date, the seller needs to be perfectly honest with potential buyers about the history of the coin.
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Pillar of the Community
United States
2600 Posts |
Roman, when you say pure acetone, is this the what is available commercially to the avg Joe? And, if not, where can you find it?
Jim
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Pillar of the Community
Czech Republic
803 Posts |
Jim, we used Reagent-Grade Acetone, but as long as it's pure, it should be safe to use on coins. You can pick-up pure acetone in any major hardware store.
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Pillar of the Community
United States
1283 Posts |
quote:
It's easily done with some hot water, aluminum foil and baking soda.
Can you elaborate? |
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Pillar of the Community
Czech Republic
803 Posts |
Paratrooper, I've included the link to the procedure in one of my posts. If you're planning to do this for a coin in your collection - I would recommend creating kind of a bezel out of foil to keep contact "burns" on the rim.
I use this method only on coins I don't care much about, or heavily-toned silver counterfeits that I am studying. (or if I'm cleaning silverware).
Use at your own risk and try it on junk coins, first.
Cheers,
~Roman
Edited by TwoKopeiki
07/18/2007 11:41 am
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Pillar of the Community
United States
1283 Posts |
Two, of course :) I just want to play around with some older, toned pocket change to see the result.
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Valued Member
Canada
86 Posts |
JUST CARL is right!!! Cleaning coins is a no no. It can remove things that you do not want removed and can add things you do not want added. Any knowledgeable coin collector or dealer can easily spot a cleaned coin and unless you are trying to sell them on ebay to some unsuspected buyer, I would stop. My rule has always been buy the best you can afford instead of settling for less and you will be happier in the long run. As for banknotes the same holds true. Using chemicals to remove things, erasers to remove pen and pencils marks, bleach to brighten etc.....All damage notes. Think twice before cleaning. Just because they sell it does not mean it is good for your coins |
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Pillar of the Community
 United States
3234 Posts |
fastback....if you've read the entire thread you'll note that your response is inaccurate. There is such a thing as non-malovent cleaning/conservation. Yes, there is. If you have no desire to test this out on your own materal, then don't....that's understandable.
The word cleaning perhaps immediately brings up a nasty connotation to many. Normally, I'd say that's a good paranoia to have. But, sometimes a proper chemical cleaning is a very good thing either to conserve a coin or to make it from something with horrid toning into something that appears to have been just issued from the Mint. And, yes, toning could be attractive, yet there truly are situations where the toning brings the saleability of a coin waaaaay down.
This whole thing about this adverse emotional reaction to the word "cleaning" reminds me of a personal analogy. As a teen and even into my adult years, I enjoyed a game called Dungeons and Dragons. My wife has a friend where early in their friendship it was mentioned that I enjoyed this game. She said...."Oh, that evil game. How can you play that? You know that it's bad for you!" I just about puked up in disgust. Obviously, somehow she got drilled into her head that role playing games were somehow bad and just repeated the drivel over again. Usually, this misinformation was propogated through religious channels.
Open your mind....it's not quite that black and white. Or in D&D terms...."good" and "evil".
Edited by Prethen
07/18/2007 1:00 pm
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Posted 07/15/2007 9:50 pm
