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 Replies: 47 / Views: 12,460 |
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Pillar of the Community
United States
1984 Posts |
About that PCGS slab: It's my feeling that despite what Scott Travers says, PCGS has an unstated policy of slabbing every coin a "good customer" submits. I'm certain the graders are made aware of when a coin "needs" to be placed in a slab. Or maybe I'm just being cynical.
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Pillar of the Community
Belgium
2078 Posts |
jaobler I am sorry my speciality is gold grading the coin is painfull on my eyes so I hope a connoiseur will answer your question  |
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New Member
United States
10 Posts |
I'm trying to become more knowledgeable about coins that have been cleaned. Personally, I would like to stay away from them, but have no idea how to detect them. This is a nice post on some examples of cleaning, but just because I can see the pictures doesn't mean I know what to look for.
Being a novice some of the terms where new to me and don't know what they mean. I'm pretty good at guessing what I'm look at but, I don't want to be the fool and assume I know what your talking about.
An example would be the coin posted by AnemicOak as being cleaned and shows me a picture. What is it about coin that says "cleaned". Again, novice I have no idea what I'm looking for.
Help!
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Pillar of the Community
United States
6384 Posts |
Hi Therisker, Your questions are excellent. Cleaned coins still give me trouble, although I'm gradually getting better at spotting them. I still get fooled sometimes. The half dollar posted by AnemicOak is not that hard to spot as cleaned. This coin has virtually Mint State details with no visible wear to my eye. As such, it should have some original mint luster which should show as bright areas and darker areas in the photo. These "hot" and "cool" areas are created by light reflecting off the microscopic flow lines that are created in a coin's surface when it is struck. Their position on the coin will change if the position of the light source changes. You can easily see this effect on any modern BU coin. Take a new quarter, for example, and tilt it under a light. You will see the hot and cool areas move across the coin as you change the angle. AnemicOak's half dollar has a washed-out, uniform dull appearance, especially on the obverse. There are no hot or cool areas. I assume it was "dipped" in a tarnish remover like a thiourea solution in an attempt to remove stains or oxidation. This treatment got rid of the tarnish but in the process the original luster was damaged. "Dipping" is one type of cleaning which may not hurt a coin too badly if it is done carefully. In this case I imagine the coin was in the solution too long and it has definitely lost both luster and value as a result. The other kind of cleaning is "abrasive" cleaning which physically damages the coin, usually leaving hairline scratches. I was finally able to copy the following image of the PCGS AU50 slabbed 1874 half dollar that I mentioned in a previous post. There are fine scratches over the entire obverse. The scratches are mostly parallel which probably indicates the coin has been wiped with an abrasive cloth. Any coin that looks like this screams "CLEANED" to me. As such, I am very surprised it was slabbed by PCGS. Somebody bought this coin for over $400, which is close to retail price for an original (un-cleaned) AU. I think they paid too much. All this is just my opinion, of course, based on what I've learned from more knowledgeable collectors and trusted dealers.  |
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Pillar of the Community
United States
675 Posts |
I am shocked that the seated liberty coin wasn't body-bagged by PCGS.... I am no expert but that is about the most obvious looking cleaning I've ever seen. Those are some NASTY hairlines!
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Pillar of the Community
United States
717 Posts |
I've seen posts regarding cleaning with acetone, lemon juice, tin foil in water with baking soda, etc. Is there a definitive way of cleaning coins acceptably? I have mostly Lincoln cents, Indian Head cents, & Mercury dimes. I bought a set of Uncirculated Lincoln cents 1954-2007. Some of the earlier coins had black stains, but they appeared Uncirculated. Some of the Indians have an adhesive on the reverse. Most of the Mercury dimes appear "dirty" with grime. What methods have people used to safely clean copper & silver, but are not considered "cleaning?" Edited by yechi7
05/10/2007 6:27 pm
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Pillar of the Community
United States
974 Posts |
I know a fellow that steams his coins with just plain hot water in a steamer and the results are amazing on some before and after examples I have personally seen.
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Valued Member
United States
402 Posts |
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Pillar of the Community
United States
7123 Posts |
The most telling giveaway especially when looking at a picture are the halo's around the lettering and devices .  If you look specifically at the 10 in the center of this coin ,,the Halo is well defined as well as the hairlines extending the change in appearance even further out from the 10. when a coin has more of the surface cleaned like the obverse of the same coin .  Then the rim,denticles and smaller details within the design become key to spotting the cleaning ,, hairlines are not always present or noteable with the naked eye,, sometimes it is just settle differences in shine,luster or perhaps even just toning that was not removed from the smaller less accessable places within the design . This coin has been abrasively cleaned on both obverse and reverse,, it is starting to retone , but it will never be what it once was . Metalman |
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New Member
United States
43 Posts |
Top Advice for cleaned coins.
Fine Lines can be seen under a microscope...
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New Member
United States
43 Posts |
@ Fishnwidow: I believe it was cleaned with Aluminum Oxide and a Drill-Press Cloth wheel. The puffy metal is definately from aluminum oxide. It creates a mirror-like shine, but fades and blurs fine details into nothingness. The ears will disapears and fine text will too.
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New Member
United States
24 Posts |
So..could anyone tell me how to clean the coin in acetone? Can you clean all types of metals? To you let the coin Air dry after or pat it down?
Thanks,
Snookless
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Pillar of the Community
United States
6384 Posts |
Hi Snookless,
When I use acetone I place the coin in a small glass and add enough acetone to cover the coin. I gently swirl the glass for a minute or two and then pour off the acetone. If there is any color to the acetone (meaning something has dissolved off the coin), I'll add some more and repeat the process until the acetone remains colorless. Finally, I tip the coin out onto a soft, clean paper towel and let it air-dry. Pure acetone leaves no residue and will completely evaporate from the coin in a few seconds.
Acetone used in this manner is safe for all coin metals, in my opinion. The are some posts on the forum about acetone causing corrosion on copper but you have to leave the coins in the acetone for hours or days before damage begins to occur. Be sure to only use chemically-pure or reagent-grade acetone. Never use acetone mixtures such as nail polish remover.
Good luck, and be careful with this stuff; it's highly flammable!
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Pillar of the Community
United States
4589 Posts |
A very interesting topic with great visual aids
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New Member
United States
24 Posts |
Thank you Jaobler...these are very clear instructions...I will try it on some newer coins that are all mucked up b4 I try it on any of my collectable coins.
Thanks again.
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Posted 04/13/2007 12:01 am
