Cleaning your Uncleaned Roman Coins
Have a tip for cleaning not included here? I want this to be the most
comprehensive cleaning section on the web!
Email it to me and I’ll put it in.
Cleaning your coins can be fun and exciting, and can also be about the most
frustrating thing on the planet! These instructions will help you along the way.
I’m starting with all of the techniques that I know and together we will build the
best list of cleaning techniques available on the web! There is no one ‘right’
method for cleaning coins. What works for one coin may be an absolute disaster
for another. The best solution seems to be a combination of methods and
experience. Experiment to find the combinations that work right for you.
The best tool is patience.
Many of the ancient coins have a patina, which is a colored layer (usually green,
red, brown, or black) that builds up on the coin over the centuries, you want to
remove the dirt from the coin and not the patina. That is the correct way to do
it. If you use a technique that removes the patina, you decrease the coin’s
value and you risk damaging the coin. Your objective when cleaning coins should
be just to remove any dirt and incrustation that obscures the coins design and
not to return them to the way they looked when they were first minted. Don’t
clean them down to the bare metal. Ancient silver coins can also have a form
of patina on them, but we call that Toning. Toning can range from a very light to
a very dark grey. A properly toned silver coin can be very pleasing to look at,
as opposed to the bright silver coins that are so common today. So please,
if you have a toned silver coin let it be.
Many of the techniques here will remove the patina. I will try to indicate when
that is the case.
Tools of the Trade
The most common tools and ingredients are:
Magnifying or Jewelers Glass
There is some consensus on what the normal way to clean a coin is:
A good first step is to wash the coin with water and dish soap. This will get
the surface dirt off. Then scrub with the toothbrush, maybe applying a little
baking soda to the coin as you scrub. Soak it in Olive Oil overnight, and
then repeat. And repeat…and repeat…and, well you get the picture.
This process can take days, weeks, or even months. Use the toothpick
to get dirt out between the letters. I find that valve oil, instead of olive
oil will work a little faster. Valve Oil will not darken the patina like olive
oil will either.It is only good if you are leaving the patina in tact, as valve
oil on the bare metal can leave some pretty funky colors. You can find
valve oil in any musical instrument shop.This is the only way of cleaning
the coins that I know of that leaves the patinas in tact for sure. The most
important ingredient is PATIENCE!
Slow and Steady may win the Race, but I want to see my coins!!!
Now for all of us who are doing this for fun, here are some of the ways to
clean them up a little faster and have the result be a beautiful
coin that you can attribute and display.
A metal pick can be a life-saver. Careful not to scratch the metal.
A dental pick works great, but even a push pin makes for a good scraper and
A Shocking Development
There is also a fast way of cleaning coins. Through electrolysis you can
quickly remove the dirt from a coin and have a nice looking coin within a
day or two. To build an electrolysis machine you will need an AC adapter,
a stainless steel spoon, salt or baking soda, a bowl, and alligator clips.
Cut the end off the cord of the AC adapter. Separate the wires. Strip some
of the shielding away from the wires and wrap the wires, each around
the end of an alligator clip. Then fill a plastic or glass bowl with water and
put in about ¼ cup of salt or baking soda (baking soda is more gentle).
Stir, then attach one of the alligator clips to the spoon, and put the spoon
in the water. The alligator clip attached to the spoon should not be in the
water. Bending the spoon helps. (Careful as bending and using spoons
and bowls can cause adverse reactions from spouse). Then put the
other alligator clip in the water. Plug it in and observe which one fizzes.
Then unplug it. If the spoon fizzed, then detach the alligator clip and put
the other one on the spoon. The fizzing end should attach to the coin.
Then attach the coin and put them in the water. Plug it in again, and
watch the dirt fly off. Before long a layer of dirt and metal will form on
the surface of the water. You will need to change the water whenever this
gets thick as it can be corrosive. I find that 20 minutes works for me, but
that may vary with the coin, the amount of water and the amount of salt.
More salt means it works faster. BE CAREFUL!! I’ll try to have pics before long.
You can get a nasty shock if you aren’t careful. Don’t go touching the water
or the spoon, without unplugging it. After each 20 minute treatment take
it out and scrub it with a toothbrush and rub it on the towel. I find that
dabs of the valve oil works well for this part. Then just repeat until you
have a nice coin. Now this usually destroys the patina which greatly reduces
its resale value, and also removes a small layer of metal, which, if there
wasn’t much on the coin before, there certainly won’t be now, but it leaves
you with a beautiful coin when done properly.
Tips from customers:
For what it’s worth, I bought the cleaner at JC Penney for $18.99. I know
it’s a terrible thing to do, but I’m going to dip the coins in CLR tomorrow
to strip away much of the patina. My daughter has show-and-tell Monday
and wanted to take “shiny” coins.
John – Mesa, AZ
Instead of a toothbrush, I found that a bristle brush from a .22 cal rifle
cleaning kit did a great job of removing some of the more stubborn dirt.
Not the brass tip, mind you, but the black bristle tip. Should be able to
find them in any sporting goods store.
Bill – New Jersey
I have had very good luck with using Calgon water softener that I bought
at the supermarket (in the laundry detergent section). After every soak
in olive oil, I clean off the oil with warm distilled water and a little soap.
Then I add one tablespoon of Calgon to a cup of distilled water, mix it in
a small tuperware style container and shake for 10 seconds. Immediately,
layers of dirt fall off and soften it so it can be more readily picked off.
Toothpicks are a little fragile and too small to get leverage. If you get the
right type wooden chop sticks and sharpen it (not all woodchop sticks
easily sharpen to a fine point, so try several brands) with an electric pencil
sharpener, you get a nice tool to use and it can be resharpened.
TOILET BOWL CLEANER! Lol. then a soaking in calgon and Joy detergent,
then a good cleaning with a brass brush. they come out beautiful Only
leave them in the the cleaner for 10-15 minutes.
NOTE FROM ROMANCOINS.NET
It appears that this method strips the patina.
However, if you are in it for the fun…so what.
I have a cleaning tip for you, It works great the best so far when
it comes to soaking compounds:
The carpet cleaning fluid that comes with “The Rug Doctor” carpet
cleaning machine you can rent from Supermarkets. Just soak the coins
full strength for 1 day at a time…You will be amazed!!!
NOTE FROM www.romancoins.net
This one looks like it leaves the patina intact.