| Author |
 Replies: 26 / Views: 3,101 |
Page 2 of 2
|
|
|
|
Bedrock of the Community
United States
20753 Posts |
|
|
Pillar of the Community
United States
3343 Posts |
It looks like a patch of sulfur tarnish, maybe from contact with the corner of a piece of paper over many years. An oxidant like peroxide would probably remove it, but it would damage the coin's patina.
I use silver cream all the time to clean tarnish off sterling silverware, but the objective is shininess not original surface preservation.
"Two minutes ago I would have sold my chances for a tired dime." Fred Astaire
Edited by thq
07/23/2020 08:47 am
|
|
Pillar of the Community
Canada
1530 Posts |
I've used NCS from NGC before and they are really good. I would let them try to remove the spot or leave it be, don't try to remove it yourself.
|
|
Moderator
 United States
189601 Posts |
Quote:
Leave it as is  I would feel better taking the money spend trying to conserve and use it to buy a better example. If it were something with sentimental value (to which I can relate) then I would not want to risk further damage. |
|
Valued Member
 United States
75 Posts |
Just a brief followup: I couldn't help myself. Washed first with diluted dish soap then a baking soda and aluminum electrolysis bath. Took off the sulfur oxide and left the silver. Now a really lovely mint luster and a sharp cartwheel on both sides. Couldn't be happier with the result.  |
|
Valued Member
United States
75 Posts |
|
|
Pillar of the Community
United States
7631 Posts |
Quote:
I couldn't help myself. Believe me, we've ALL been there! At least the "pie" toning on the reverse is mostly gone now. I still think it's been dipped a few times over the last 40 years and the mint luster is long gone. If you like it is really all that matters though. It's a nice type coin till a better one comes along! |
|
Moderator
United States
56855 Posts |
Quote:
I couldn't help myself. Washed first with diluted dish soap then a baking soda and aluminum electrolysis bath.  At least it didn't make it look all the worst for cleaning it. As a general rule to others: Do Not Clean Coins.John1  Edited by John1
07/29/2020 7:19 pm
|
|
Pillar of the Community
United States
5833 Posts |
This will labeled as "Harshly Cleaned" if it were to be graded by TPG. |
|
Pillar of the Community
 United States
5679 Posts |
I'm sure it's shinier, but I doubt there is any mint luster left. But as long as you're happy with the look, that's all that matters.
|
|
Bedrock of the Community
United States
17884 Posts |
Quote:
Now a really lovely mint luster and a sharp cartwheel on both sides From the image I suspect the mint luster/cartwheel is gone. |
|
Pillar of the Community
United States
4469 Posts |
Thanks for posting the results.
|
|
Valued Member
United States
75 Posts |
"This will labeled as "Harshly Cleaned" if it were to be graded by TPG." Regarding this comment and some others: The coin looks with the eye... not magnified as in the scans I did... as a lovely AU example with a good deal of mint luster and a true cartwheel shine. I did not "scrub" the coin with bicarbonate of soda. I used the "electrolysis" method of immersing in a hot water+dissolved soda bath on an aluminum foil sheet. Same as electroplating except this mix transfers the the oxide to the aluminum and leaves the silver intact. Yes, if the tarnish was left long enough, the damage on the surface will still be visible and grade as "cleaned" but the black oxide disappears. This method has no noticeable effect on the mint luster. If, like me, you want the "eye appeal" to be as close to an uncirculated coin as possible for a simple "type" collection or "year of birth" mint set that looks amazing, give this method a try with coins of low or moderate value. |
|
Pillar of the Community
United States
5679 Posts |
Your method results in a redox reaction that removes sulfide from the underlying silver, but you're assuming that the remaining surface silver atoms aren't changed from their original structure. It's probably just as safe as a quick dip, but there's no question that the process will eventually affect original mint luster.
|
|
Valued Member
299 Posts |
It's been cleaned at least once, and the reverse is an organic stain which will be difficult to remove without surface damage to the coin. I wouldn't do anything to it other than possibly replace it.
|
|
Page 2 of 2
|
Replies: 26 / Views: 3,101 |
Page 2 of 2
|
First Page
Posted 07/23/2020 08:45 am
