Sometimes used with gems, a rock tumbler can also be used as a coin tumbler. Tumbling is a technique for smoothing and polishing a rough surface. Realistically speaking, a tumbler should mostly – if not only – be used on clad coins. It is a mechanical cleaning process. You will need to either buy or build your own tumbling system as well as a specific mix that has to be added to the process.

However, you can also build your own mix. A lot of “recipes” can be found on the Internet. Here are a few:

  1. Daisey BB’S, Borax, fish rocks & about 1/2 cup water.
  2. 60% lemon juice and 40% vinegar. Some go as high as 90% lemon juice + aquarium gravel.
  3. Same recipe as above but reversed proportions: 40% lemon juice and 60% vinegar.
  4. CLR, Vinegar, Salt, dish soap, and water and aquarium gravel.
  5. Vinegar, coarse salt and aquarium gravel.
  6. Salt, vinegar, aquarium rocks, and a few larger rocks.
  7. wood chips or sawdust, a squirt of liquid dishwashing detergent, a couple tablespoons of vinegar and some fine polishing grit.
  8. Some use walnut shells instead of gravel or rocks, when cleaning brass.

Some additional tips:

  1. Try to clean up to 30-40 coins at a time. The maximum load should not exceed half of your barrel.
  2. Time-wise, some people run their tumbler for 2 hours and it is sometimes enough. Some leave it running overnight. (Be careful though as when a batch lasts too long, it may start deteriorating the surface of your coins) It might be a good idea to check on progress once in a while. Every 2 hours is my advice. (I did read that some people advise checking every 30 minutes though! In my opinion, you are pretty safe with a check every 2 hours)
  3. Now that part is crucial! You  may put together dimes, nickels and quarters. Don’t mix them with cents! Those will actually bleed on the other coins and give them a brownish/reddish look! If you separate your items, you will be successful and your coins will be shiny as new.
  4. After the cleaning process, clean thoroughly your coins with water. (Otherwise, they sometimes get a little white residue on them)
  5. Please consider using a tumbler when it comes to cleaning clad. Banks will not accept dirty coins and this cleaning process is rather easy. Please do not put your dirty coins in a cash machine.
  6. Some clean all cents together. Some separate into different batches pre-82 cents, and 82 and above cents. (Honestly, I did the experiment not separating them, it works fine)

Below are some pictures of my first experiment (and I made several rookie mistakes!) As you can see, mostly clad quarters, dimes and nickels.

I went with the recipe #2. As I did not have any aquarium gravel or rocks or even walnut shells, I just went with lemon juice and vinegar. (about 60% – 40%). I placed the coins in the barrel and prepared the mix separately.

I then poured the mix into the barrel and just covered the coins with it. Try to limit yourself to a half container.

Reassembled the barrel and let it run. For my very first batch, I waited 2 hours, checked in and the coins were already good looking. They did look a little brown though. I then had the tumbler run for an extra 2 hours.

Below are the results. As you can see, even with my rookie mistakes (not using aquarium gravel, going with a rather long session, and putting way too many coins in the tumbler), the result is clearly satisfying! I did get an answer about that brownish color… I told you not to mix clad and cents, remember? Well… I did find the culprit… There was ONE cent in the mix! Be extra careful when picking your coins. DO NOT MIX CLAD AND CENTS! Overall, I would certainly recommend using a tumbler to clean clad and even cents.

  

Here is an additional “recipe” you might be interested in trying out. From Alan John Moody, posted on the Facebook group “Restoring Your Finds – Metal Detecting”

“Some will not agree with my methods but sometimes you have to fight fire with fire. Our nickles in Phx come out of the ground pretty toasted. Tumbled in muratic acid for about ten minutes then rinsed well and tumbled with water and baking soda to neutralize the acid for about 5 minutes.”

The result speaks for itself…