Provincial Romans Ancient Coins & Antiquites

Alternative Cleaning Methods

3. Manual Cleaning.

The latest and greatest method of manually cleaning a coin involves using small brass tools or rods. Many thanks to John Ryan for coming up with this great invention! Homemade Brass Tools

Brass Tools

Using a wet stone or small file, you create the end that you need or are most comfortable using to remove the debris. The above photo shows three different sizes of brass rods, the larger for total "crusty" coins and the smaller ones for the more detailed work. I found using a mechanical pencil (medium rod) and compass (small rod) easier than trying to hold them. The beauty of brass is that it is either softer than or equal to the metal of the coin, thereby preventing undue scratching. Be aware however that even with brass you can damage a coin, so always go slowly and gently.


"Super Tool"

In 2002 I was offered the opportunity to "Beta-Test" this tool and must admit that I have been unable to put it down ever since! The brainchild of Souzana Steverding, a frequent contributor on uncleanedcoins@yahoogroups and co-moderator for the Ancient Coins for Education (ACE) at, she combined the knowledge of brass tools presented by John Ryan with Kara Ann's, (Where are you?), idea of using a pottery tool, to come up with the next generation of ancient coin cleaning tools!
What makes this tool so different? Since the brass tip is now curved, there is less chance of scratching your coin like I do with the pointed tool. You can still cause damage, but with a soft circular motion, you can remove tremendous amounts of dirt and encrustations with half the effort and less damage to the coin! There are so many different variations you can try, for example, using the outside edge to push debris from the coin and using the inside with a pulling motion to "cut" into it. Also, you can use different sizes of brass rods for different cleaning techniques. The smaller the diameter, the more cutting the tool becomes and the more dangerous to the patina and metal. I've found it effective on both dry and wet processes, but prefer the wet process of keeping the coin wet/clean while working on it. Note that this does not replace the brass tools above, it just gives you more options. You'll still want the original brass tools for the lettering, devices and other detail work.
The best part is that the Stanley Hobby Knife is available for about $3 and the solid brass rods can be found at some hardware/hobby stores for less than a dollar. The 10-401 comes with a small blade that can be removed and replaced with the brass rods. Additionally, the Stanley "head" can be replaced to use other sized accessories and attachments. Some assembly required! ;) Just snip off about 1 1/4 inch of the brass rod, bend it to form the curved tip, push the two ends together as much as possible, insert the two ends into the holder vise and tighten hard.
(I've already found an alternative use for this amazing tool. I've always had trouble with California water build-up on my plastic glass in the bathroom. Well, this incredible tool takes it off quickly and easily, without scratching the plastic!)
Some final comments. This discovery is a prime example of a group of people working together and sharing ideas in an open format that leads to great inventions like this one, the brass tools and even the discovery of the benefits of distilled water use. My special thanks to those experienced "cleaners" who have so graciously and openly shared their years of experience and knowledge! I would imagine we'll have another year of these wonderful discoveries ahead of us, so don't be afraid to experiment, you might be the next one to take us all to the next level of cleaning these ancient beauties! :)

4. Preventing Damage.

Magnification is the key! To really see what your doing to your ancient coin, you need to see "up-close & personal." Normally 3-10x is the preferred magnification and there is a wide variey of styles, lighted, adjustable, etc. Ideally you'll want a model that allows you to work hands free. Several different models of hands-free magnifiers and visors, etc, can be found on the auction sites at prices ranging from $5 - 15. If you want to do it the way the big boys do however, you'll need to get a stereo microscope. Usually 10x is preferred, but some use up to 30x. Make sure that the field of view fits all your coins and if you can, get one that allows for a camera attachment. Overhead light is nice but any lamp can be substituted and underneath lighting is totally useless for coins. The purpose here is to ensure that you are not damaging your coin. With the naked eye, it is easy to imagine that there is no damage occurring, however under magnification, you discover, to your horror, that you've just created the Grand Canyon on your coin. Remember that the professionals can take weeks and even months to clean a single coin. Patience!

Here is the Steroscope I purchased off eBay for just under $200.

Stereo Microscope (10, 20 & 30x)

Here is the view of the above ancient coin at 10x. Note that this microscope does not have a camera attachment, which is why the whole coin isn't showing.
View at 10x from Stereo Microscope


Carelessness or failure to follow established electrical and/or biohazard safety standards can lead to serious injury or even death!

5. Electrolysis

The following procedures are given freely and without any warranty implied or otherwise!  Use at your own risk!!

Electrolysis should normally only be used on the worst case coins. Normally called a "crusty" coin (photo on left below), it is a coin that is totally covered in a cement-like substance that soaking and tools just won't remove. Again, this system is NOT for coins that are attributable, rare or showing visible details. This process will quickly and efficiently destroy any patina and even the coin itself.  Here is a picture of a "crusty" & what it turned out to be:

 A "Crusty" Ancient Coin

a) Supplies you will need:

Usually a power transformer or battery charger that operates in the 500-800 milliamp range and no more than 12 volts. I highly recommend the following adjustable adapter. It not only allows you to operate between 1.5 - 12 volts, it has a reversible polarity switch should you get your wires mixed up. Price was $9.95 at the local OSH hardware store.

Adjustable Adapter

Two electrical clips, a plastic or glass bowl or container and a piece of stainless steel. My wife got tired of me stealing the dinnerware, so I started using stainless steel bolts.

b) Ideally, you should use distilled water in your plastic or glass container, however tap water will work. I have also found that using baking soda allows for a slower and more controllable cleaning than using ordinary table salt. I usually use one large tablespoon of baking soda per quart of water.

c) It is important to remember that the positive (usually red) wire goes to the stainless steel and the negative (usually black) wire goes to the coin. When setup is running, bubbles should rise from the coin side of the connection. If not, your wires are backwards. It is important to know that even at low voltage, it is not pleasant getting a shock, so please ensure you use common sense and try not to kill yourself.  Here is my current rig after two days usage. If you think it looks bad, try using salt for two days!

Electralysis Rig
Make note on how the bubbles are rising from the small clip? Also, it is important to note that the positive clip will dissolve just as quickly as the stainless steel if allowed to sit in the water. Also the closer the coin is to the stainless steel, the faster it will work. Just remember to not allow them to touch each other!

As you become experienced (please use culls to practice with) you will get a feel for how long a particular coin will take. Normally, I'll run the rig for fifteen minutes and then scrub the coin and if not free of encrustations, back in the bath for another fifteen minutes, repeat. Highly recommend that you purchase a simple timer as it is very easy to forget about the coin and come back an hour later to find that you've dissolved a 1,600 year old coin.

A few items for your consideration.

Electrolysis creates a hydrogen gas that can be both harmful and explosive. Always ensure adequate ventilation and a fresh source of oxygen. A fan is highly recommended.

If a coin has serious encrustations, it is usually from the coin itself. So if you clean it with electrolysis, you'll usually get to see what hole all that gunk came from. Sometimes it's the entire coin! :(

Once you start any cleaning process, it is important to know that the process may not stop, just because you removed the coin. Always use distilled water soaks after zapping and cleaning your coin. Using any brass tools after electrolysis will usually leave the coin as shiny metal, which is not appreciated in the numismatic world. Ideally, if you keep your electrolyte solution, your coins will come out of the soup with some toning. It goes without saying that any and all patina (protective coating made over time) will be gone!