I have been watching a lot of You Tube metal detecting videos and all of the coins found are some level of dirty. Some are completely crusted with dirt or caked with mud. I cringe every time the finder start wiping off the dirt between their fingers. But I get it, they are doing it to see the type, date, etc. Since we are told over and over again, NEVER CLEAN YOUR COINS, what is the best practice for a mud caked coin that may have been in the ground for 50 - 100+ years?
Welcome , realizing how much damage may have already occurred, and the possible current deterioration, I would put them in a bucket of tap water and a few drops of detergent, mix and let stand for a day, and then rinse dirt away and separate out any desirable coins. These I would further clean with tap water, with last rinse of distilled water, followed by a dip in either 91% isopropyl alcohol ( walmart )or other such as acetone if you are familiar with its safety needs) and let air dry. Further treatment would be considered based on any perceived value of the specific coins. MOST will be spenders. Jim
I totally agree with you! I hate when they do that. See, I have more patience. When I dig out my coins and I find one really dirty, I just put it in my pouch and keep searching. When I get home then I clean them gently in warm water!
I started a Metal Detecting Club over the summer. One of the guys uses a small spray bottle to rinse of the dirt and mud. He named it the Fufu Bottle. I am the tallest to the left side.. next to the teen kid.
As long as it's just mud & crud from the ground, freeze, thaw, heat & freeze it a few times in a small glass of water. No detergent, no handling, no nothing except watching the dirt disappear with only water ever touching the coin.
The suggestions here are good, but don't expect miracles. Being in the ground really does a number on a coin. Gold coins can generally come through it alright provided they survive the excavation process: gold is very soft, and you can easily damage, scratch, or cause hairlines on the coin. Silver and copper are much more reactive than gold, so you will likely end up with "environmental damage" after a relatively short time buried, but, sometimes not. And, sometimes, you can rescue silver coins by dipping them, but I wouldn't count on this.
I've been known to spit on and rub crusty dug coppers in my fingers (if you've watched that in my videos, you'll have seen me do it, and apologize). But only the crusty copper that has a pretty thick encrustation. I wouldn't do this to a silver coin, usually. Sometimes the excitement of a find just takes over and you have to see what the date on a coin is, that's all I can say. Even when you know better, it's second nature to want to do that. A little bottle of water of course is a good thing to carry around, whether you spritz the find or soak it.
One that I've done is to heat some hydrogen peroxide solution (drugstore first aid strength, not the industrial stuff) in the microwave, until it is just about to boil. Plop in crusty coins. Watch 'em fizz like an antacid tablet. Watch the crud come off as they bubble. Rinse, pat dry with paper towel or cloth. Repeat as necessary.
Not sure I'd do that as H2O2 is a fairly strong oxidizer. I wonder if soda water wouldn't be just as effective?
We are talking about heavily encrusted stuff that's not too corroded or unstable- just encrusted. I've found the peroxide method similar to electrolysis. With both, one would probably want to be cautious with heavily corroded or otherwise "unstable" pieces. I ruined my first dug large cent trying to clean it with electrolysis, which had otherwise done well for me, particularly on silver. The coin was a 1796-1807 Draped Bust cent- I could just tell from the faint details when I dug it- but it was already corroded. In my misguided attempt to coax a date off of it with electrolysis, I "burnt it up"- because it was already pretty heavily corroded, it ended up a featureless slug after the electrolysis. So yes, there are good candidates for the peroxide treatment (or electrolysis) and other things that are perhaps not so much. With either the peroxide or electrolysis treatments, a very short exposure might work well. I just "zapped" that large cent for too long in the electrolyis solution. A minute or less, and it might've been OK (or at least no worse than it already was when it came out of the ground).
