Rapid Cold Coin Cleaning Method
Duration: 4-7 days
Patina: Generally removed
Over several years I have come up with a good way to get fast results if you are not worried about loosing the Patina. A super way of cleaning all of your really Stubborn and previously uncleanable coins to get the best possible results without having to spend days on each coin. This works particularly well for bulk cleaning. After all the steps have been followed it will leave you with a pleasing finish to the coins along with maximum visible detail even on heavily worn coins. This process will not damage the actual coins, but will aggressively remove the crustacean, dirt and Patina. The coins shown here had all been in Olive Oil and Lemon Juice for twelve months with no signs of being cleanable before being cleaned in Just 4 days with this process.
- Olive Oil
- Liquid Descaler
- Two plastic tubs or containers
- Wooden spoon
- Towels, cloths
- Baking Tray
- Access to oven
- Disposable rubber gloves
- Washing up liquid
It is good practice to wear rubber gloves when using any chemicals, even household ones. The chemicals can irritate and the Wax being used here can make your hands pretty dry. Also getting the dirt out from under your nails can be quite frustrating!
1 Place your encrusted ancient coins into a plastic container. Depending on the volume of coins to be cleaned, you can use a lunch box with a lid right up to a bucket.
2 Add 50% Olive Oil, then add 50% liquid Descaler into the container. This should comfortably cover all of the coins.
3 Regularly stir the solution with the wooden spoon, or if in a lunch box with a lid you can shake it, ideally you should do this at least once a day. The olive oil actively attracts all of the dirt while the Descaler goes to work in a slow and steady fashion to break the crusts down.
4 Over a period of a few days you will see the olive oil turn into a thick Brown, Green, or Grey solution as all the dirt and crustacean moves into the oil.
5 You will soon get used to knowing how long to leave them in this solution from experience. Generally you will notice some visible Bronze on most of the coins when the solution has worked well enough.
6 Place your coins into the Sieve and rinse thoroughly with water, keep shaking or stirring them until the bulk of the residue has been removed.
7 At this point I normally put a little washing up liquid into the Sieve and rub them all together in between my hands to get the rest of the loose dirt off. The foam will turn a dirty colour then rinse under the tap again until they are clean.
8 Once you have completed the Rinsing and washing of your coins, you need to sort them out. For this I normally do it on a Towel. I generally spread a handful of them evenly on one edge of the towel. Then sort them out putting the "mostly" cleaned ones into one container (as they will come up even more after we finish cleaning them), and the ones that would definitely benefit from further cleaning go into a fresh container to start over with again to repeat the process (using fresh solution as per point 2).
9 Put the oven on at 250 degrees and wait for it to pre heat, put a few of the cleaned at a time into a baking try and try to evenly spread them around so that they will bake evenly so that all the moisture is removed and any remaining dirt bakes properly.
10 Bake them for about 45 minutes, normally about half the way through I take the baking tray out and turn them over using the wooden spoon or a flat metal spatula. Return them to the oven and continue for the remaining time. Once they have been baked I then remove them from the oven and let them cool down until they are just like warm.
11 Now place them into a plastic container with some liquid Furniture Beeswax in and give them a good shake around. I normally use liquid "HG Furniture Beeswax". You will see that the solution turns into a liquid and gets really filthy as it removes the last of the dirt.
12 Pour the contents onto a towel or absorbent cloth and then rub them all until all the excess has been removed. I sometimes also use old socks for this as it stops them going all over the place. Give them a good rub for a few minutes together, the dirty wax settles in the relief giving them a darkened detail and darkens the overall colour while sharpening the detail.
Now they are done you can set about attributing them or just seeing what you have found. This process really brings the detail out to an "attributable" standard on even the most worn Bronze or previously uncleanable ancient coins. It removes the maximum amount of dirt and crust, and then enhances all the reliefs of the coins. And over time they just look nicer and nicer as the Bronze continues to naturally darken up.
For examples of cleaned coins, please see our 'Cleaned' section.