View Full Version : Conserve or leave?
04-04-2013, 08:17 PM
I have a question for the group. Below is a coin I purchased about a year ago. On the obverse there are a few tiny green spots in the hair, but on the reverse rim at 12, 2, 8 and 10 there are considerable green stains. I thought this was verdigris - but while reading Scott A. Travers book "The Coin Collectors Survival Manual" on the first page of chapter 20 he says "blue/green colored flecks and stains are due to chemicals in the PVC bleeding out of the film onto the coin". I suspect that's what is on the rims. He suggested "Koinsolv" but I've read that could be a problem. Should I try soaking in Acetone or Xylol then rinsing then Verdi-Care - leave it alone - or send to NCS for professional conservation? Thank You for your thoughts on this coin - before I do anything.675676
04-04-2013, 11:15 PM
Hard to tell exactly from the picture but I think that is corrosion, not a stain. Unlikely Acetone or Xylol would remove that particular type of corrosion. It appears as though in a couple spots it has eaten down a bit, for example the spot at K11 & K2 on the reverse. On the obverse isn't anything too substantial to worry about. I have noticed, in my experiences of working with corrosion, that there are numerous types that respond to different techniques. Most likely the reverse spots would not come off without use of an instrument to tap on it to break it loose. Sometimes it breaks off, sometimes it is very stubborn and can result in undesirable results -DAMAGE- if done improperly. I would not experiment with that coin, as it is quite nice, other than a Xylol bath and some Blue Ribbon/Care/Verdicare. The bath and conditioning will remove any moisture and prevent the corrosion from spreading by sealing it up to the open air. Sometimes you get lucky and you end up with a very green cotton swab and a coin without any spots!! I picked up a very inexpensive Indian Cent that I thought was toast, coated in heavy green, and it dissolved away in seconds with Xylol leaving a very nice AU coin with just a stain on the surface--not sure it was corrosion in hindsight as it just came right off and no damage to the surface other than color. Other coins, where corrosion has eaten into the surface, the damage is done and all you can do is prevent further damage. If you remove the green it leaves a low spot and trust me there is not nice glossy patina under the corrosion! :( I am also attaching pictures of an 1839 N12 with corrosion that Xylol & Blue Ribbon treatment did not budge. I have not attempted any other removal options on this coin, it is as I received it. I may try tapping those spots at some point but I know the coins is eaten into so best case is prevent further damage.
Perhaps some others will chime in, I am certainly no expert just sharing my own experiences of working with corroded coins. Bottom line, do your experimenting on some common Lincoln Cents, culls, or even ordinary pocket change.
04-04-2013, 11:20 PM
I concur with Copper Frog. This looks like a good candidate for removal with a soft rose thorn.
04-05-2013, 05:40 PM
The 1803 is in far better condition than the one that I have! I would leave it as it is and not conserve it. The photos are good but I would guess holding it in hand would give a better idea of flecks and stains. Practice on a few cull Indian Head or Lincoln Head Cents first before you plan to conserve it. It would be of interest to see the end results if you go ahead on this Large Cent.
I too, have much to learn about copper conservation practices.
04-08-2013, 09:04 AM
I concur with Copper Frog and weckberg on this one.
04-09-2013, 03:43 AM
Sometimes I use my thumb nail to scrap off the green. Then use Care.
04-10-2013, 08:03 AM
I vote for sending it to NCS. They have done some real magic with several pieces I have submitted.
04-16-2013, 06:39 PM
I have scraped a coin with my thumb nail before. I would recommend against this idea. Left it bright orange where I touched it.
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