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 Replies: 17 / Views: 6,446 |
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Valued Member
United States
224 Posts |
No question about it -- electrolysis DESTROYS patina. But if you have a coin that seems to be cast in good Roman cement instead of struck in bronze, then electrolysis can have its place. Often there's not much left under the corrosion, but why soak a coin for a decade to probably find a slug? But sometimes after electrolysis you find some nice surprises. My advice for electrolysis: - Use a weak solution of sodium carbonate. (Arm and Hammer WASHING soda in the supermarket.) - Use a low power cell phone charger as your power supply. - Use only a carbon/graphite rod for your anode. Nothing else. Do NOT use stainless steel as some do. And the clip that holds the rod should not touch the water. Google "electrolysis" for info on hooking it up and how to tell the anode from the cathode. Here's some pics. #1 a pre-'82 copper penny with moderate wear and patina. #2 same coin after 10 one-hour electrolysis sessions. Patina was gone after one session, but after ten you will see no pitting or damage to the metal. I once tried 30 sessions with the same result. The pitting you see on the old Roman coins is from the corrosion, not the electrolysis. #3. Some crusties that will get zapped if soaking isn't working. #4. A coin I recently cleaned with electrolysis. Note: I never use darkener, just a bit of Ren Wax. An earlier pic I posted of this coin looks shiny because it was photographed in bright sunlight. #5. My elaborate and complex electrolysis lab. :-)      Edited by gtkwml
06/06/2018 09:30 am
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Valued Member
 United States
224 Posts |
Note: second photo of the penny only looks silvery because of different lighting. It is still pure shiny copper colored.
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Pillar of the Community
 United States
6514 Posts |
Prefacing my statement with I have never cleaned an ancient coin.
If used properly and with good experience I see how electrolysis can have its place.
Check out my counterstamped Lincoln Cent collection: http://goccf.com/t/303507 |
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Pillar of the Community
United States
606 Posts |
What do you do with all the slugs? I cant imagine keeping a bucket full of slicks. P.S. As an electrician, your setup give me anxiety......I kinda want to try it now.  Edited by Half
06/06/2018 10:41 am
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Valued Member
Canada
66 Posts |
Nice results! I have seen some terrible "cleaning" jobs using electrolysis .. as
I am sure most of us have.. Just pure destruction.
Looks like you have a pretty good handle on it and there is no denying the end product!
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Moderator
 United States
23731 Posts |
I have been collecting ancient coins for a good many of years now and have seen plenty of coins that have been zapped. It's easy to tell that they were by the stripping away of the patina and the pitting it caused to the surface. It may not damage a modern coin in the same way as an ancient one just because of the age and compensation of the metal, but it does pit the surface on ancient coins. Again I strongly suggest to never use this method. There are many more safer methods to clean ancient coins.
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Pillar of the Community
United States
3474 Posts |
Quote:
There are many more safer methods to clean ancient coins. For those of us not so familiar with ancients, what are the prefered methods of cleaning them? |
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Moderator
United States
23731 Posts |
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Valued Member
United States
224 Posts |
I have tried multiple sessions on Roman coins as tests, but never caused pitting. But -- as you say -- every case is different. And may be alloys I haven't tried. But one way to certainly destroy with electrolysis -- screw up and put the coin on the anode!!
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Valued Member
Canada
66 Posts |
I have never used electrolysis. But I see no issue in trying a "Hail Mary" on coins like this. This is after 7 months of olive oil, distilled water, brushing, etc. I was successful with a bunch of coins from this lot - but have 6 or 7 like this. They are beyond being salvaged and I don't think electrolysis will help either.. but I have no issue if someone wanted to try. I gave them a nice brush for this photo and now they back in a fresh distilled water bath. I do not expect any improvement.   |
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Valued Member
United States
224 Posts |
A proposal -- I'm guessing that many of you have backgrounds in technical fields like myself (much of it in chemistry). So we like to draw our conclusions based on hard data. Two things are obvious -- being buried for centuries puts corrosion on Roman coins, and 2. Zapping removes the corrosion and exposes the underlying pitting. This also removes the portion of corrosion called patina. But there still seems to be some question as to whether zapping, properly done, can cause additional pitting or damage. So far, I have never been able to cause pitting on any coin, old or new. However, as someone mentioned, there may be other alloys that might be damaged. Could some of you please experiment on some low value coin and see if you get the same result? You could even use a pitted trash coin but see if the zapping adds further damage. Just use the method I mention above. And do NOT, as I once did when careless, hook up the coin to the anode. Complete disaster!
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Valued Member
United States
224 Posts |
Claudius, I would not be surprised if zapping reveals an image on that lower left surface. Use one- hour sessions, brushing between them. The fun is in seeing something gradually revealed. And if you're like me, you will need to have two boxes -- one labeled "total slug", and one labeled "some image, but not enough to identify". :-). Have fun!
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Valued Member
United States
224 Posts |
Claudius, this may be just like seeing the image of a man on the moon, but, having seen many coins like it, that lower left image looks like it might be a very common image -- a fallen horseman being speared by a Roman soldier. The coin is upside down.  Edited by gtkwml
06/06/2018 5:37 pm
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Valued Member
Canada
66 Posts |
Yep looks right - good catch. The chances of it being a Fallen Horseman are pretty high.. get a ton of those in these lots. If you deal with a lot of Late Roman Bronzes (LRBs) like I do I suggest you look at purchasing this book.. it is amazing and for $24 well worth it. You may even be able to find it in .PDF form online for free.. not sure: It is an excellent guide to attribute the coins. https://www.amazon.com/Guido-Bruck/e/B00RXIPNIQ |
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Valued Member
United States
224 Posts |
Thanks for the tip, Claudius. I went right there and ordered a copy. Though The earliest coin I've gotten was from the reign of Tiberius, most are indeed late Romans.
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Valued Member
United States
224 Posts |
I usually use numismatics.org/ ocre/ identify, followed by a visit to wildwinds.com/coins/ric/ i.html
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Replies: 17 / Views: 6,446 |
Posted 06/06/2018 09:23 am
