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 Replies: 112 / Views: 14,625 |
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Pillar of the Community
 United States
1291 Posts |
The acetic acid test turned out to be a total dud. 3 days of soaking and absolutely no noticeable change whatsoever on the coin.
I've now moved on to a 45% concentration of liquid potassium hydroxide. This is nasty, nasty stuff. In the "good old days" you could find lesser concentrations of this stuff than what I'm using here in liquid Drano.
Anyway...I'm guessing that what dissolves hairballs and grease probably will NOT do much to silver. The quarter has been sitting in it for about 20 minutes now and I don't see any change. I'll check it again before I go to bed and then again tomorrow morning.
If this fails I'll be trying Nitric acid next.
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Pillar of the Community
United States
672 Posts |
for the nitric acid if it is conc. put it on with an eye dropper over the date like you would for a Buffalo nickel, that would be my guess |
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Valued Member
United States
397 Posts |
I've got a thought. You're basically cleaning a coin that is dateless in an attempt to figure out what the date is, correct? I see that you are tying to get the date to "pop" out similar to what you do with Buffalo nickels. With the nickels, you are causing the nickel to dissove leaving copper behind. It sounds like you are trying to dissolve some silver, leaving the copper behind on the SLQ. Why not try to dissolve the copper, leaving the silver alone? Is there a chemical that does that? The result would be an incused date - but is that a concern? |
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Pillar of the Community
United States
672 Posts |
waredu,
you have an interesting theroy but copper is a very stable metal when it comes to dissolving it. The only things I know of that will do it are High stregnth Nitric acid, and high stregnth sulfuric... unless someone else does. Neither of these acids really dissolve it though... its a really really slow process. And both of these would also disolve silver. Cu is used in coins because of this.. very few environmental processes will ruin it.
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Pillar of the Community
United States
672 Posts |
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Pillar of the Community
United States
3294 Posts |
I think copper should dissolve easier then silver, but I dont know if removing 10% would be enough to get the date to pop out.
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Valued Member
United States
397 Posts |
I thought copper was more reactive than silver, which is more reactive than gold.
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New Member
United States
43 Posts |
I'm seeing what looks like a "3" about where the last digit of the 1st piece should be. Interesting to see how this works out. Could be a good way to score some rare pieces...
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Valued Member
United States
186 Posts |
Diluted Nitric Acid has worked the best for us... we use the test acids that come with a gold testing kit.
22k acid is the strongest 10k acid is the weakest.
I start with one drop of 10k and one drop of water.... wait a bit and then rinse quick... then work my way up the scale until something good happens.
I try to cover the entire face of the coin, so that there isn't that "acid spot" right at the date.
Sometimes I'll do the Reverse just to even it out. Then a little soak in Ketchup, and rub some oil into it by hand. Not perfect, but I have "saved" a lot of rare dates this way....
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Pillar of the Community
United States
1291 Posts |
Waredu - Go back to the 2nd page of this thread to see the photo of what Nic-a-date did to a copper pipe.
Mslibertysbeau - Are you referring to the first quarter that I have pictured on page 1 of this thread?
CEOcoinshop - I'm not following you... You say you start with a drop each of Nitric and water and try to cover the whole face of the coin. Isn't that spreading it a little thin?
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Valued Member
United States
397 Posts |
How about diluted Nic-a-Date? I saw the picture, and that was after about 6 hours, right? I was just wondering what would happen with less time and a diluted solution. I have no real idea though how to get rid of the black patina that Nic-a-Date caused. My wife teaches high school chemistry and agrees that copper is more reactive than silver, but she's never thought about this and doesn't know of a particular acid or base that would work.
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New Member
United States
43 Posts |
Yes, I was referring to the 1st quarter after the first dipping. Latecomer to the thread.
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New Member
United States
43 Posts |
I don't really know about the chemistry of date restoration, but it seems to me that a good cleaning of surface debris and wiping of the surface with a gentle, washable dye to in effect fill the valleys and temporarily accentuate slight variations in elevation would be the best approach to "restoring" a date.
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Pillar of the Community
United States
672 Posts |
mslibertysbeau- A dye would work if there was a prtial date and you wanted to see it more clearly. I have not heard of doing this but your theroy would seem to work. What he is trying to do is dissolve some of the coin away leaving the date. When the coin is struck diffrent densities are formed that fall away at diffrent rates. I believe that is the theroy behind what they are attempting to do.
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Valued Member
United States
467 Posts |
Maybe try electrolysys? If Silver is more conductive, with some fine tuning of the set up you should be able to remove silver from a coin and leave the copper.
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Replies: 112 / Views: 14,625 |
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Posted 08/21/2010 09:52 am
