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Author Topic: Electrolysis cleaning?  (Read 212054 times)

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Offline Raymond

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Re: Electrolysis cleaning?
« Reply #25 on: September 25, 2006, 04:00:50 pm »
The "zapping" is definitely a shortcut that I don't mind experimenting with on coins that to my untrained eye show little promise, such as dark smooth disks that barely offer a shadow on the surface, or a particularly rusty and cracked scyphate.
I have a small lot of uncleaned Greeks that I would never ever subject to such treatment!  Right now, they're simply soaking in olive oil.  I don't even want to use a brass brush on them.  Frankly, I'm scared to scratch or hurt the coins in any way and that's why after ten days, I still haven't played with them! 
The same goes for what I think might be a lepton, it's barely 10 mm in diameter, quite thin and I can't feel any ridges on the surfaces of the coin, yet there appears to be some faint colouration of what might be a pattern...  Am I wasting my time?
Raymond
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Offline saholz

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Re: Electrolysis cleaning?
« Reply #26 on: January 12, 2007, 04:57:16 pm »
I might as well add my two cents worth.  (Appropriate choice of words, I must say).  No one will argue that a coin with good detail and a lovely patina should be left alone.  In the world of uncleaned coins, however, that's not going to be a common sight.  Most of the coins we see are covered in dirt over a hard, crusty surface.  The question then becomes, how much of this encrustation must be removed to bring out the details of the coin?

Any time we clean a coin, surface material must be removed.  If a nice green or brown patina completely covers a coin to the point of obscuring surface detail, is it better to leave the coin obscured or remove as much of the patina as is needed?  My own opinion is that I'll remove as much of the surface encrustation or patina as I have to in order to show detail.  There are many coins which are so badly encrusted, however, that my normal cleaning regimen of distilled water soaks, scrubbing with nylon and brass brushes, and mechanical cleaning with dental picks and fine Dremel tips, just won't do the job.  It's at this point where the really difficult choices must be made.

If I absolutely can't get through the coin's crust with conventional means, I will then try lye soaks.  I know this will eliminate most, if not all, of any remaining patina, but I personally would rather have a lye soaked coin, that I can identify, than a green unidentifiable lump of crud.  Many of the worst coins I've had, have come out of a lye bath in surprisingly good shape.  To me, lye is a last resort that can provide good results if the coin still has good metal, poor results on porous coins.  It has the advantage of leaving a brown patina on the finished coin.

I've used electrolysis on many of my truly hopeless coins.  Sometimes, a coin is so heavily encrusted that even the lye won't break through.  In case like this, I will zap a coin.  I've had much less success with electrolysis than lye, probably because I only use it as a very last resort on my worst coins.  Zapped coins always require re-patination of some sort.  I really can't stand the bright brassy look of the coins as they come out of the solution.

So, in the end, this all comes down to a question of degrees.  How far are you willing to go to uncover the actual surface details that an encrustation may hide?  Nobody strips a perfectly good coin, so all we're talking about here is how we deal with coins that need to be cleaned in some form.  I don't think there's any right answer for all coins.  I've made mistakes with coins, where further cleaning actually destroyed what little detail was left and preserved in the patina itself.  I've also removed patina, or even stripped coins, in the cleaning process and wound up with coins that were stunning in their detail. 

I wish there was an easy and "correct" answer, but I don't think there really is.  We all want to wind up with the best coin we can after all the work we put into cleaning these things ... how we get there is likely to be an endless debate.

Stan

Offline Scotvs Capitis

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Re: Electrolysis cleaning?
« Reply #27 on: February 01, 2007, 02:24:25 pm »
Victor, what is the dirt-brown looking stuff in your coin in its uncleaned state? That coins looks like one I might have tried to clean with a diamond dusted dental pick. Your electrolysis results though are very nice indeed. There is a place for it, despite some who consider it pure evil.  :)
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Re: Electrolysis cleaning?
« Reply #28 on: April 13, 2007, 05:33:31 pm »
A couple more thoughts on electrolysis from a new-bee:

There's probably no point to mixing lemon juice and baking soda.  I don't know if it makes a good electrolyte, but you're mixing an acid and a base, so you're probably not getting the acidic effect of the lemon juice.  However,  I'm not a good enough chemist to say if you're creating better ions to carry current, or a more neutral pH solution that's better for the coins, but it sounds like an odd thing to do.  Now, I have noticed a base-like residue around coins after electrolysis, so I've thought of adding vinegar or lemon juice (to a salt electrolye), in order to have a slightly acid solution, to remove this residue (the generation of which, by the way, I can't explain).  Does anyone have any lore on this?

My big question is whether anyone can actually say why they think a salt solution (for a short period) is worse for the coins.  Current is controlled by the voltage, the concentration, and the proximity of the coin to the other electrode; it's not just driven by the choice of electrolyte.  So salt doesn't have to "burn" the coins.   I can assume that the chlorine ions (from salt) would ultimately be bad for the coins (bronze disease), but the chlorine (Cl-) is going the other way in electrolysis, away from the coin, to the positive electrode, so I'm not sure I see the problem.   Sure, the cholrine would get after the bronze after awhile, but so would the washing or baking soda, it would start eating the metal.  That's why they use a very low (5%?) concentration in the washing/baking soda combination used in soaks to stop bronze disease.   Are sodium ions worse than calcium ions? 

Enough problems, here's and answer and a helpful hint:

It's good to have bubbles at both electrodes.  That means you're getting action at the coin, and also the bubbles at the + electrode means your producing gas oxygen instead of oxidizing the + electrode and breaking it down.   I'm sure you've seen someone's rusty setup.

I've found that the best electrode material is carbon (not iron or stainless steel).  You can by carbon electrodes made for electrolysis at chemistry places, cheap, or you can cut open an old D size battery (NON-akyline NON NON NON or it squirts out dangerous liquid).  They eventually wear out, and can turn the water kind of black, but they're not creating bad ions.

PS:  I only use electrolysis for "hopeless" coins that trying to clean mechanically would ruin worse (wearing away lettering etc).  And, I soak the coins in distilled H2O afterward.

PPS:  I'm afraid of lye, and I also think it would quickly re-oxidize the coins.


Offline bruce61813

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Re: Electrolysis cleaning?
« Reply #29 on: June 29, 2007, 02:20:43 pm »
You can scrub off the crude every once in awhile. It is the stuff that comes off the coin, and it does tend to become an insulator. But there is never a lot of current flowing in the system.

I find that a low voltage, 6 VDC and low current, less than 1 amp, works fine. I only work with one coin at a time, and as others have noted, it takes awhile to clean the coins. But if you take it slow, you can stop before you get to bald metal.

Bruce
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Offline AdonisRock

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Re: Electrolysis cleaning?
« Reply #30 on: December 13, 2007, 03:03:39 am »
hey i decided to give this a go on some crusties i have,  seeing as my brother wouldn't let me use his battery charger for his motorbike (i believe his words were 'You're a [expletive] idiot, you will [expletive] kill yourself.' i've hooked it to a 6v battery out of a dolphin torch.  after about 15 minutes the water had turned yellow and there was a brown foam floating on the surface.. I've just chucked a full crusty in there and i'm gonna leave it overnight and see what happens.  I'll post results if there is anything interesting to tell. 


*edit* ok, so the crusty didn't work, the coin didn't start bubbling, and the spoon i was using grew like a blue fur on it??  I was using sodium carbonate.  Perhaps the battery is to weak? since there is not really any exposed metal, just rock.

I have replaced the crusty with another coin that appears to be a slug, with a thick black patina, and am using mediterranean sea salt from my pantry.   and it has started bubbling away, I will leave it in there a few hours and see if anything happens.

Offline Raymond

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Re: Electrolysis cleaning?
« Reply #31 on: December 25, 2007, 08:12:39 am »
 :o Never ever use salt as an elecrolyte, the CL will corrode the coin.
Raymond
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Offline AdonisRock

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Re: Electrolysis cleaning?
« Reply #32 on: January 03, 2008, 03:12:45 am »
Following up from my last post, I've zapped a few coins, the small crusties stripped back to bare metal in a couple of hours with the 6 volt batteries, but came out as junk, No great loss as I never would've gotten through the layer of rock otherwise to see what they were.  I also left a larger coin overnight which turned out to be a decent Volusion.  Now i'm trying some first century near-slugs and crusties, so we'll see what happens.

Raymond- I have been using Sodium Carbonate, as opposed to table salt.. I realised I was just being impatient, and sometimes I'd have to wait 5 or ten minutes for it to start for some reason? maybe I should mix the water well in advance to make sure the crystals have all dissolved properly.

All in all this setup seem to be pretty good, especially on larger coins. 


Offline Raymond

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Re: Electrolysis cleaning?
« Reply #33 on: January 03, 2008, 07:04:52 am »
If the edges of the coin start turning blue, or the coin looks like something picked out of ashes of a barbecue pit, you are probably using too much current, i.e. your amperage is too high / resistance too low.  I obtained decent results on a couple of coins using a simple used 9v transistor battery, in bursts of 5-10 minutes; I would pick away at the coin after every "therapy" session.   Slow is better and it is possible to "overcook" the coin.
Decent additional info on zapping can be found at http://tomross.ancients.info/.  Just remember, it's not a cure-all and is not the lazy person's method to clean and avoid using elbow-grease which is what I was looking for!
Raymond
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Offline bruce61813

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Re: Electrolysis cleaning?
« Reply #34 on: January 03, 2008, 12:04:32 pm »
Quote from: bruce61813 on April 13, 2007, 11:20:35 pm

If you want and intresting experiment, take a teaspoon of lemon juice in 4 ounces of olive oil, mix very well, add a crusted coin and heat.


I am not feeling all that adverturous today.... what happens?


This is for silver coins only, it works but is not good for copper based coins. The result is rapid, safe removal of encrustations from silver coins. But it will remove all oxides and oxide formations, so debased silver will appear pitted if the copper is really oxidized.

A second note, you can't really control the current during electrolysis, you can control the voltage.  Also sodium carbonate is a poorer electrolyte that sodium chloride, therefore the current will be less, and as was mentioned, the chloride in NaCl has long term effects on the coins. If the edges of the coins turn blue, you are over heating them, the blue indicates that the edges have reached annealing temperature [about 900 deg F] for copper, and that is way too  much energy.  As I noted earlier, I use a plug in source of 6 volts, maximum current of 1.8 amps.
It is slow, but does a good job. Also I use a mix of sodium carbonate and sodium bicarbonate [actually I use Gringgotts #1] .

Bruce
too many coins - too little time!!

Offline Raymond

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Re: Electrolysis cleaning?
« Reply #35 on: February 26, 2008, 09:50:29 pm »
The crud that accumulates on the (-) anode (?), I believe, does scraping it off hasten the reaction?
Raymond
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Offline Mayadigger

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Re: Electrolysis cleaning?
« Reply #36 on: February 26, 2008, 10:38:57 pm »
Ave!

The crud that accumulates on the (-) anode (?), I believe, does scraping it off hasten the reaction?
Raymond

It does for me!

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Offline Raymond

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Re: Electrolysis cleaning?
« Reply #37 on: February 26, 2008, 11:38:41 pm »
keep zapping or go mechanical now?
Raymond
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Offline rick fox

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Re: Electrolysis cleaning?
« Reply #38 on: May 31, 2008, 04:04:24 pm »
I use electrolysis for cleaning the uncleanables.  My process is incredibly simple.  A plastic container, an electrolyte and a 12 volt battery.

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Offline Robert_Brenchley

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Re: Electrolysis cleaning?
« Reply #39 on: June 01, 2008, 06:51:31 pm »
here's a coin that was, until now, a total loss to me, tons of encrustations.  Too bad I didn't take the before pic.  Now, it's still worn, but I can see something!  I'm assuming it's a Ric 85, Claudius II with Salus AVG rev.  Can't tell if it's IMP C CLAVDIVS or IMP CLAVDIVS...
I zapped it :evil:
Do I smooth it out with black rubber bullets and then Dellarize? Or will my attempt to smooth sand off the little that remains of the details?
Raymond

Dellerise it as it is if you want to, but otherwise it's done.
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Re: Electrolysis cleaning?
« Reply #40 on: July 22, 2008, 01:27:07 am »
I want to suggest carbon electrodes for those doing electrolysis
(instead of spoons, or what-ever).  You can buy them for very very
little $ from hobby chem stores or sites.  They tend to break down after
awhile, but the carbon is inert (compared to a metal), and you don't get
a huge mess of rust or other by-products.  Just hook an aligator clip to
the top, out of the solution.


FYI:  My personal inclination is to save electrolysis
for only those coins so encrusted they can't be realistically
mechanically cleaned, or ID'd

Offline Danny S. Jones

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Re: Electrolysis cleaning?
« Reply #41 on: July 30, 2009, 11:18:11 pm »
I could post a few before and after pics here, but I'm too ashamed. I've zapped coins straight to Hades trying to clean them. It's a process I'll never use again. Not that I like to clean coins. (At least not right now, after 4 hours of scrubbing and picking.)  I'm sitting here right now looking at 121 globs of dirt-crusted Roman relics on my desk. Some are in olive oil. Some are in piles. Some are in plastic holders. I spent the last four hours with my five year old daughter scrubbing coins with a toothbrush. As a matter of fact, right now I'm HATING coin cleaning. I just irreparably damaged a coin by stripping the patina off and finding absolutely NOTHING underneath. Not that I was trying to strip the patina. Three strokes from a nylon bristled toothbrush did the trick. It all came off... the legend, the mintmark, the image. Everything.

To all you zapp-happy folks out there, please remember that PATINA IS THE COIN. Sometimes there is nothing below the patina layer except a beautifully flat and rusty plug of useless metal.

Offline Jaimelai

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Re: Electrolysis cleaning?
« Reply #42 on: August 08, 2009, 12:19:37 am »
At this point in my ancient coin cleaning career, I only zap the occasional blank slug - just to see what may be hiding beneath that smooth encrusting patina.  Nine times out of ten you find only a shiny metal cratered moon surface, but every once in a while you find something like this.

It started as a nearly smooth slug that I had found beneath a layer of hard mud/clay which I had previously removed  by soaking/scrubbing/picking.  There was almost no detail showing and a large red boil.  I thought for sure that beneath the red there would be a deep pit, but I zapped it anyway.  After about 30 seconds I could see the encrustation starting to fall off, so I removed the coin and gave it a quick soak in DI followed by some poking under the microscope with a sharp bamboo skewer to loosen the now blacken encrustation, then a quick brush with a toothbrush in DI water.  Still some remaining encrustation, including the red boil, so the process was repeated.  A little more came off revealing more coin detail, but still the boil remained, so the process was repeated.  This time the rest of the crud came off including the blister which only left a small rough patch behind (in the upper neck area).  This coin was has not been re-patinated or waxed, just brushed with a soft nylon brush prior to taking the pic. It was a the 96th coin of a lot of 100 uncleaned coins, but it may have been the best of the lot.

Offline bruce61813

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Re: Electrolysis cleaning?
« Reply #43 on: August 08, 2009, 03:45:00 pm »
This link may help a little
http://www.monitorcenter.org/preserving/process


For those of you that like to use electrolysis, you will note if you read the the reference CzarMike provided uses a low voltage, 3.5 volts or so, not 9 or 12 volts. I use a 4.5 VDC unit from Radio shack. It is small, about 1 inch x 1.5 inches x .75 inches, think of a small match box. It is capable of 1500 ma, so there is power if needed. Also note they use a base electrolytic solution of sodium carbonate or sodium hydroxide. Never use NaCl, it will ruin your coins. the low voltage works slower and allows time to mechanically work on the coins between sessions. I use the BD treatment mixture instead of just sodium carbonate, as it works the same, and will help neutralize the effects of salts.

Bruce
too many coins - too little time!!

Offline Constantine IV

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Re: Electrolysis cleaning?
« Reply #44 on: December 31, 2011, 08:50:07 am »
After trying Electrolysis on a "Victory Advancing" coin of Valentinian, I regret doing so. I would say it is better to use "natural" cleaners like distilled water, vinegar/lemon juice. Then brush of any crud with a nylon brush. Patience is the virtue. I found that given time, it is easier to clean, the "hard to clean" parts become easier to clean of, even by nail. Electrolysis just seems to make a mass of dark goop, rather than actually clean.
And in the end, some coins are damaged by time, and it is irrepairable.
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Offline Lee S

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Re:Electrolysis: Beginner Help
« Reply #45 on: February 28, 2014, 10:20:15 am »
A tip for the impatient cleaner (aka something that I wish I had known when I first started zapping...)

If you know that you are going to be stripping the coin down to the bare metal anyways, try to get as much of the crud off manually before zapping the coin.

I thought that electrolysis was going to be a quick and easy cure, but the more junk there is on the coin, the longer it will take to zap (and we're talking hours in some cases).


Thanks for sharing information..I will try out the method as I need to clean lots of old coins and hope it works.

Hi Adolph...

  Remember that electrolysis is generally a method of "last resort", to save for coins that have not responded to the time tested methods of soaking in distilled water, olive oil, or one of the many solutions available for sale out there...

 Also, if you have "lots of old coins", remember that not all will require the same cleaning process, if you zap them, you will have ( if they are good quality ancient romans, for example..) perhaps a 1 in 10 return... ( if you are lucky!) and you will have coins stripped of patina.. and unless you are REMARKABLY lucky, most of their value...

If you use the traditional soaking and scrubbing method you may have a 50%+ return... ( I am plucking these figures out the air... it depends entirely on the quality of the coins you start with, but the ratio will remain the same... a minimum of 5 to 1 better success with soaking and scrubbing )

 If you post some photos of the coins you are going to clean in a new thread then you will get more detailed information from one of the many experienced cleaners on here, but you must remember, you cant have your cake and eat it... I have cleaned coins with electrolysis with spectacular results, but I also have a jar full of blank slugs, some of which, with hindsight could have been attractive additions to my collection!!!

 Best wishes,

Lee.
 

Offline areich

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Re: Electrolysis cleaning?
« Reply #46 on: February 28, 2014, 10:57:18 am »
See? That is the reason why I would always advise against it. A few people may be able to judge accurately which coins will profit from electrolysis but most will use it as a weapon of mass destruction.
Andreas Reich

Offline bruce61813

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Re: Electrolysis cleaning?
« Reply #47 on: May 25, 2014, 04:19:13 pm »
I will make comment that i have made many times before:

1. Never use salt water [NaCl and water] as the electrolyte bath. this is too highly conductive , and the current flow will burn the coin.

2. Use a soda bath, a mix of baking soda and washing soda or just one of them, gives a very slow and controllable clean. Used with a 6 vdc source and you will find it very controllable.

3. Connect the coin to the correct terminal, it should be the  negative (cathode), if you see a lot of bubbles coming off the coin, you have it on the wrong terminal.
this could be a reason for a silver coin being destroyed, the silver was dissolved as it was the positive [anode].

It does work, work in 3 to 5 minute runs, with scrubbing between trials.


Bruce61813
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