by Allen Morgan
DISCLAIMER: I cannot be held responsible for damage to you, your
home, or the object being cleaned using this method. This is risky,
and can result in either a fire or an explosion if not done properly.
Ok, you've found a nice silver coin or ring, but it's
heavily tarnished. You want to clean it up, but don't know how. Well,
I'll show you how I clean my silver. However, I must warn you, you
can really damage a coin or piece of jewelry by doing this, so be carefull.
Electolysis is an easy way to clean heavy tarnish off
of silver, aluminum tokens, copper pennies, etc. I don't really recommend
using electrolysis for coppers, as the verdigris, or green oxidation,
is actually the surface of the coin, and if you remove it, you get a pitted
surface that is hard to read.
Electrolysis works in a couple of different ways. In
layman's terms, current is passed from the transformer through the wire,
then to the object being cleaned, through a solution of water with an electrolyte
in it (ions will transfer, allowing the current to pass, distilled water
won't work very good), and is "picked up" by the other electrode, and returned
to the transformer. Water is split, at the coin, by the electricity
into hydrogen and oxygen. Remember that these are the components of
rocket fuel, and are highly explosive. Make sure to do this in a well-ventilated
area. The bubbles that form will loosen any dirt, paint, corrosion,
etc., by forming under that and knocking it off the coin. Corrosion
on silver is typically silver sulfide, and the current produces a chemical
reaction in the silver sulfide that frees up the silver, and combines the
hydrogen produced by the water with the sulfide, resulting in hydrogen sulfide.
This gives off a faint rotten-egg stink, which is itself a good reason
to do this in a well ventilated area.
I usually use 2 - 3 cups of hot water, and about a
tablespoon of salt to provide electrolytes. Some people use washing
soda, but I haven't tried this.
I always like to have a little dish with a paste of
baking soda and water handy to drop silver objects into, about 2 T baking
soda and 1 T water, as this helps to neutralize any chemical reactions going
on after the current is stopped, as well as polish the object.
First, you need a corroded object. I typically
only do this for silver coins and jewelry that have either been submerged
in the water for decades, or were lost and eventually buried in a low-laying,
wet area, like a mud puddle or other swampy area. Here's a likely
This one came out of an area that is well known for
giving me tarnished silver. It's one of the low-laying swampy areas,
of which Michigan has plenty of. You can try just polishing this with
a paste of baking soda and a little water, but experience has proven that
it won't help that much.
I use a universal AC/DC converter that I bought in
the electronics department of a store for about $7. As you can see,
it has a slide switch for regulating the voltage. I keep it maxed out
You'll want a reactor vessel of some kind. It
needs to be non-conductive. Glass will work. I like the margarine
tub, as it's cheap (i.e., free), but it needs to be cleaned out with hot
soapy water before you can use it for electrolysis.
You have to connect the item to be cleaned to the current
somehow. Stainless steel alligator clips are what I use. You
have to be careful about how hard you clamp onto the coin, as you can scratch
Depending on which electrode you attach the coin to,
you are either cleaning the coin with electrolysis, or plating the coin
with gunk. There is an easy way to test which electrode you want.
Submerge the two clips, and keep them separated. Plug in the
adapter. The one that starts to fizz is the one to attach to the coin.
You'll want to attach something to the other end that will enter the
solution without submerging the copper wire (the copper will dissolve over
time). A stainless steel spoon is what I use. Never, NEVER, let
the two electrodes, or the submerged objects, touch while the current is
on. Your adapter will short, and possibly cause a fire.
You'll want to attach something to the other end that will enter the solution
without submerging the copper wire (the copper will dissolve over time).
A stainless steel spoon is what I use. Never, NEVER, let the two
electrodes, or the submerged objects, touch while the current is on. Your
adapter will short, and possible cause a fire.
In this photo, you can see that I've got the spoon
and dime in the solution. You want to submerge the dime, but not totally
submerge the alligator clip. Also, you'll notice that I don't let the
metal objects touch.
Now, it's time to plug in the adapter and let the current
do it's thing. Remember, the dime should fizz, not the spoon. Here's
a picture of what it will look like as it happens:
Now, depending on how heavily
tarnished the coin is, you will notice some black "gunk" coming off. This
is normal. In fact, quite a lot of black gunk can enter the solution.
I only apply current for a couple of minutes, then unplug my adapter,
remove the coin, and rinse it off. If it's pretty much clean, I'll
drop it into the baking soda paste and rub it gently to polish it.
I like to rinse the alligator clips as well, as the
salt from the solution will start to rust them (see the pic of the clips
above). I also like to change alligator clips about once a year. They're
cheap, and a small bag of them from either a hardware store or Radio Shack
will last quite a while.
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