HOW TO clean your coins with electrolysis
	CLEANING COINS
			Beachcomber (How To Tips)
As all detectorists are aware, long-term burial in corrosive soil, or immersion in salt water, doesn't do the appearance of most metallic objects any favors. Regrettably, tarnish, rust, and corrosion are the natural consequences of chemical interaction with most metals.
Many methods have been devised to remove the various forms of oxides, sulfides, carbonates, chlorides and assorted types of verdigris from metallic objects. The method employed most often by professional conservators of recovered metallic objects is electrolysis, a process wherein the object to be cleaned is submerged in a special, electrically-charged chemical solution which causes to corrosion to disintegrate.
The purpose of this article is to inform Beachcomber Inn visitor"s how they can build an inexpensive electrolysis machine which will do a splendid job of cleaning coins or other small metal artifacts.
The first thing you will need to obtain, if you don't already have one, is a 9 to 12 volt AC adaptor, often called an AC/DC convertor, or battery eliminator. This is the same electrical device which plugs into an electrical wall outlet and lets you operate portable radios, cassette players, and so forth, without the use of batteries.
When choosing the AC adaptor for your mini electrolysis machine, take note of its rated output. This will be printed somewhere on the adaptor, and will usually be listed in milliamps (1/1000th of an ampere) which is designated by the symbol "mA," as in "350 mA." The higher the output, the faster the cleaning effect; I recommend the selection of an adaptor of at least 300 milliamp output.
You will also need several small electrical "alligator clips," a stainless steel spoon, a non-metallic cup or small bowl, water, and some common table salt.
To convert your AC adaptor into an electrolysis machine, first cut off the little plug device from the end of the wire. (The "plug" referred to here is the one that connects to the radio, cassette, etc., NOT the one that connects to the wall socket) Once you've removed that little plug, you will note that the wire to that little plug is a double-strand wire; beginning at the cut off tip, very carefully separate (pull apart) those two individual strands of insulated wire for a distance of about 6 inches, leaving the insulation intact on each of the wires. Next, strip away about a quarter to a half inch of insulation from the tip of one of those loose wires, and where the insulation has been removed firmly affix (crimp into place) an alligator clip. Be sure that there is a good electrical contact between the bare wire and the alligator clip. Now, repeat that procedure to the other strand of wire. You will now have two single-wire sections, each with its own alligator clip.
Now, make up an ample supply of electrolyte solution, at the ratio of 1/2 teaspoon of common table salt for every 8 ounces of water. Pour some of this electrolyte solution into the cup, nearly filling it. Place both alligator clips into the solution, being careful not to let them touch one another. Remember, once we plug the adaptor into the wall socket, electrical current will be flowing to the alligator clips, and if they touch one another, the adaptor will short out, and be ruined.
After you've made sure that the alligator clips are not in contact with each other, plug the adaptor into the wall socket, and watch to see which of the two alligator clips begins to produce bubbles. The one that begins to bubble is the cathode, or negative pole of the AC adaptor. The side that does not bubble is the anode, or positive electrode. Unplug the adaptor, remove the alligator clips from the solution, and in some way mark the polarity of the wires.
Bend the stainless steel spoon into a sharp "U" shape so that, when hung over the lip of the cup, the "bowl" of the spoon can reach about half way deep into the cup.
Hook the cathode ("bubble side") alligator clip to the portion of the spoon which is outside the cup. Hook the anode to the object to be cleaned, and suspend it into the solution, over the edge of the cup opposite the spoon, and use one of your spare alligator clips (or a clothes pin, etc.) to secure that artifact-holding wire in place. You want to be sure that the object to be cleaned is fully immersed in the solution, and suspended more or less at the same level in the cup as the bowl of the spoon.
Once that is done, you are now ready to begin the electrolysis cleaning of your artifact. Making sure that the two electrodes are not touching, plug the adaptor into the wall socket. Within moments, the object to be cleaned should start producing bubbles. If not, unplug the adaptor, and reposition the alligator clip on the artifact, preferably at a point where metal is showing. Then plug the adaptor back into the wall socket.
Once the coin or artifact is merrily bubbling away, then everything has been done right. So what is taking place? During electrolysis, ions (atoms which either have an excess or deficiency of electrons, and thus are electrically charged) are liberated from the poles, and these migrate through the electrolyte solution to the oppositely charged pole. The cathode, to which the artifact is attached, is the point of entry of anions (negatively charged atoms with a surplus of electrons) into the electrolyte solution. The liberation of anions, from the chemical compounds which constitute the corrosion on our artifact, triggers chemical changes within those compounds, causing them to disintegrate into less complex chemical substances. Proof of these chemical changes are seen not only in the artifact becoming progressively more clean, but also in the discoloration of the electrolyte solution as dirt and various chemicals are released into it.
How long does it take for an object to become clean? That depends on how badly it is corroded. After a few minutes, unplug the adaptor, remove the coin or artifact from the solution, and gently rub it with your fingers or a soft toothbrush to remove loosened corrosion, then rinse it thoroughly in clean water. If it is acceptably clean, then there is no further need for electrolysis. If it still needs further cleaning, return it to the solution, and resume electrolysis. This process may have to be repeated several times for badly corroded or heavily concreted objects. During this process, should the electrolyte solution become notably discolored, replace it with fresh solution.
Several things should be kept in mind regarding electrolysis. First, it should be remembered that corrosion progressively affects the metal of the object, and in advanced stages of corrosion little or none of the original metal may be left; in other words, all that may be left is a lump of corrosion more or less resembling the original object. This is especially true if the object was made of thin metal to begin with, or if the metal was one that corrodes especially easily, such as tin, aluminum, etc. Sometimes, severely corroded objects will crumble away to nothing when submitted to electrolysis. Thus, you will have to make the decision whether submitting a particular object to electrolysis will likely be worthwhile.
Also, don't be in too big a hurry to clean every object you recover. Keep in mind that cleaning off the layer of corrosion will merely reveal "what's left" of the object, and in some cases, that is not very impressive. If the object has reasonably good patina and is aesthetically pleasing, leave it "as is."
A word of caution: from time to time, feel the AC adaptor to determine if it is getting too hot. If so, disconnect it, to let it cool off. Such overheating will occur as the artifact becomes progressively cleaner. This, in turn, allows for a greater flow of electrical current to pass through the adaptor, increasing its temperature. Thus, never leave your electrolysis machine on and unattended for any length of time.
Careful use of your mini electrolysis machine will help transform many of those ugly blobs of corrosion into beautiful coins and relics.
		BACK TO THE MAIN PAGE

>