| Author |
 Replies: 18 / Views: 2,943 |
|
Pillar of the Community
United States
1372 Posts |
I think this is something worth sharing. I know...NEVER clean your coins. The truth is that conservation is sometimes necessary. Sometimes you just have to do it. The trick is to not ruin the coin in the process. I picked this coin up on ebay for 36 dollars ppd, willing to gamble that I could make it presentable enough for a type set. It's a nice AU Seated Liberty quarter...BUT...it had this ugly stuff on the back that needed to be removed. I tried warm water...and that turned the stuff a bit sticky, but would not dissolve it. I tried Naptha...nope, that did nothing. Next up...acetone...Nope, that's not the solvent. Now out come the big guns....paint stripper....nope, that wouldn't touch it either. Mind you, I have not abraded this coin in any way to this point. Every solution was carefully applied...no mechanical action, but the results...were practically nothing. The coin was still encrusted with black substance that really looked like tar....which had been heated and blistered. I did notice though, that through this intervention, a few places on the rim had shed chips of the material....sooooo....I came up with this idea. I took a piece of masking tape and stuck it to the reverse of the coin, and using a pencil eraser, rubbed the tape into the deepest recesses that it could reach. The picture of the tape shows how much "crust" the first application was able to remove, and the second application is the piece of tape holding the first one down. The masking tape removed a lot of the contaminant, but there was still more that I thought would lift off of the surface, so I switched to a cellophane tape with a lot higher "tack" and did it 2 times with that tape. Every time it left less on the tape, until the last time I did it, it scarcely removed anything. While it's not yet where I would like it to be, it's back in the acetone soak for now, and looking much better than before....and the coin did not incur a single hairline from mechanical cleaning. Note...despite the bad picture, the surfaces of the coin are not damaged. I'll eventually get some better pictures, but for the purpose of this post, these are illustrative enough. Thought I'd share. Chancellor Sutler    Edited by Chancellor Sutler
12/22/2009 03:30 am
|
|
|
|
Pillar of the Community
Canada
1082 Posts |
Interesting.
I recently acquired a coin in an assortment that exhibits the same tar-like material on it. It appears to be a 10 cent coin from British East Africa or similar (can't see because of the tar).
I'll have to try the masking tape. Thanks for the tip.
|
|
Bedrock of the Community
United States
19935 Posts |
Tape....an interesting physical method....definately a new one to me. You should always step through the polarity ladder when attempting conserveration instead of just throwing solvents at the coin. I describe the process in this thread: https://goccf.com/t/57008Lincoln Cent Lover!VERDI-CARE™ INVENTOR https://verdi.care/
|
|
Pillar of the Community
 United States
1372 Posts |
I did read that post before starting on this coin. I thought I followed the progression close enough, but didn't know where the naptha (lighter fluid) fit in. I figured that since Acetone wouldn't dissolve it, there was little chance of harm, and little chance that it would dissolve the contaminant. In that respect I was right.
Any advice as to what the "last" step should be prior to sticking it in my Dansco album?
Chancellor Sutler
|
|
Bedrock of the Community
United States
19935 Posts |
Lighter fluid is simply a lipophilic hydrocarbon, namely butane (CH3CH2CH2CH3). It's mostly a mixture of the two butane isomers n-butane and isobutane. Xylene would have been a much better choice since a much larger molecule and more likely to solubilize long-chain residues.
Final step should be an acetone rinse, pat dry, and put in your album.
Lincoln Cent Lover!VERDI-CARE™ INVENTOR https://verdi.care/
|
|
Pillar of the Community
United States
1372 Posts |
The zip strip paint remover contains xylene, and that wouldn't touch it either.
I did the adhesive tape routine again, and used a very sharp toothpick as a brayer to stick the tape to the minor areas around the devices and legend. It's back in the acetone soak now, and my camera batteries are on charge, so I'll add a picture of it a bit later.
Thanks for your input.
Chancellor Sutler
|
|
Pillar of the Community
United States
1372 Posts |
...and here's my 36 dollar Seated Liberty quarter "with motto" ready for the album. The reverse is brighter than the obverse, which did not have these problems, and I should have taken a picture of that too, but there's such a software conflict between easyshare and my computer...that it's too late to do that tonight. I am pleased as punch with the way this turned out. Chancellor Sutler   Edited by Chancellor Sutler
12/22/2009 03:35 am
|
|
Pillar of the Community
United States
2797 Posts |
Looks cleaned.  btw, what does the obverse look like? |
|
Pillar of the Community
United States
1372 Posts |
It looks something like this....but in flourecent lighting..with this camera, the image is not the best. Color reproduction is always too blue, and it gets kind of washed out. I'm still learning on the pictures end of things, and really ought to consider a better camera. Chancellor Sutler  Edited by Chancellor Sutler
12/22/2009 10:26 am
|
|
Bedrock of the Community
United States
11951 Posts |
Good job. You took a ugly coin that most would not want and made it look a lot better. I would put that in my type set book.
|
|
Moderator
 United States
23522 Posts |
|
|
Pillar of the Community
United States
1372 Posts |
It actually looks quite nice in hand, and considerably better than the pictures. Aside from the reverse being brighter, it looks quite "normal".
|
|
Bedrock of the Community
United States
20753 Posts |
That is rather a new one on me. Most people spend a lot of time and money attepting to remove tape and tape glues from coins. Of course all the previous attempts may well have loosened the contaminates so the tape worked do to that, maybe. Then too remember that there are numersous brands and types of masking tapes on the market and you may have been the lucky one to pick just the right one. Regardless, that coin sure is improved.
|
|
Pillar of the Community
United States
2541 Posts |
...um....yeah... I'll second what BadThad said!
|
|
Pillar of the Community
United States
968 Posts |
I'd say it is great for a personal collection. But if you send it in to get it graded I suspect they will slap a cleaned annotation on it pretty quickly. Although, if you were to sell it you will probably get more money for it looking like it does now than it did when it was so grimy.
|
|
Pillar of the Community
United States
1372 Posts |
There are some coins that deserve the attention of a TPG...and some that don't. This one's in the latter category. I wanted an inexpensive representative of this type, and this was the best way I found to do it. I think that once it tones down a bit, it probably would grade....remember, you can't "really" see what this one looks like because of the crappy picture. I wish the obverse looked as good as the reverse, which still has substantial mint luster remaining, and which is not hairlined at all. These pictures were good enough to suggest just how effective lifting an insoluble contaminant from a coin via tape can be....and that's all I intended. I wouldn't dream of trying to sell the coin from these pictures....though I am sure I could make money on it. Then I'd need one for my 7070 again, so I'm just going to quit while I'm ahead. I have 3 coins chosen for my initial submission to PCGS....an 1883 CC Morgan that's 63-64, an 1822 Overton 101 Bust half that's easily a 63, and maybe higher, and an 1880 Shield nickel in AU. I need to decide what coin No 4 will be. Perhaps a modern gold commemorative. I really need to dig a bit though. I'll bet I have something better than that for the 4th coin. I might as well get my money's worth out of the 4 free submissions. No sense in sending something of low monetary value if I don't have to. Chancellor Sutler |
| |
Replies: 18 / Views: 2,943 |
Posted 12/21/2009 9:46 pm
