A Batch of Uncleaned Ancient Coins

Not really, most salts have pretty high water solubility. For table salt, it's like 33% or so.

Also a quibble, but the water doesn't absorb the minerals, it dissolves them. Additional mechanical action is needed to "knock" the dirt off. Shaking can accomplish some of these and let you keep soaking, also take a toothbrush and cut the bristles to half-length to stiffen them and use that to remove more dirt.

 

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Soaking coins in water will remove any dirt that is still on them. I hate to be the one to throw cold water on your coin-soaking project, but all the coins you've received have already been cleaned down to bare metal. You are unlikely to see any improvement in them by soaking them in tap, spring or distilled water.

The two coins that you are soaking still have some encrustation on them. Soaking will not remove this. You'll need to use a harsher treatment, such as electrolysis. (Some members prefer to use lye, but I don't recommend this.)

The good news is that your are unlikely to do any serious damage to the two coins that you are soaking because they are common types and already pretty well worn, so this might be an opportunity for you to experiment with using electrolysis to clean coins. Then, if you get some legitimate crusties--coins with so much encrustation on them that the seller really has no idea what is under the encrustation--you'll know how to clean them with electrolysis and what to expect from the process.

Here's some information about electrolysis:

https://department.monm.edu/classics/COINS/data/cleaning/electrolysis.htm

However, this site says to use salt as your solute. Don't use salt. It's too corrosive. Use sodium cabonate (Arm & Hammer Washing (not baking) Soda) instead. You'll find it in the laundry detergent section of your grocery store.

 

Interesting. I just figured that the water soaked into the dirt and loosened it up a little bit. I was perplexed while looking outside by my AC units. There was no runoff pipe! I remembered I had a drain in my basement, and that is where the pipe is located. It was dripping water, but that area has been subject to a few floods and therefore the interior of the condensation runoff pipe is very dirty. I will either make some or buy some. Thanks for all the information!

 

I also noticed that a lot of the coins are already as cleaned as they will be. You're not throwing any cold water. I am still going to keep this thread running to show my efforts in cleaning and identifying any and all that I can. I thought about electrolysis, but I did not think that these two needed it yet. I could have been wrong. After soaking these, I will probably try to use electrolysis with these. I have a few solutes that would work, but I have not considered which are too corrosive. Salt / NaCl would definitely be too much, especially since it turns the water yellow from chlorine. If the tap water can start bronze disease, this definitely will! Is sodium bicarbonate an acceptable solute? I watched a video on YouTube showing electrolysis on some Roman coins, but it totally stripped the patina. I will definitely check that link you sent out!

 

Yes, electrolysis will strip the patina. But coins will repatinate over time.

I have added sodium bicarbonate to salt to reduce the acidity of the water--as the salt breaks down into ions the water becomes acidic--but I haven't tried it by itself, so I don't know how well it will work. Sodium carbonate works so well that once I discovered it I stopped experimenting with other solutes.

 

Yes, but electrocuted coins almost always have unattractive pits or tough surfaces. Electrolysis should always be a last resort for coins.

 

Reading this has encouraged me to put the uncleaned coins my daughter gave me for my b-day in a tupperwear type container with some soapy water...photos when i take them out for the first time.

 

If the coins aren't super valuable, or if they're beyond help, then lye has the possibility of some amazing results.
Results not guaranteed. However, sometimes it's great.

A great result:




A bad result:



Depending on the encrustation, distilled water is a better, less-destructive result:



Another option is vinegar:






From best option to worst option, in my opinion.
1. Distilled Water is safest option, but can only be used for relatively minor encrustation.
2. Lye is highly destructive, but can cut right through just about anything.
3. Vinegar is less destructive than lye, but leads to a rather rough finish.

 

I've been known to lye but it doesn't hurt to start with soap and water...

 

Yea haha nuclear option should only be a last resort. Plus every time I mix up some lye I have an irresistable urge to drink it. Slowly going crazy

 

When I mix lye (NaOH or KOH), I cough. BTW, here is one I cleaned with KOH.

 

I’d consider that a...

 

Thank you...(I won't show the flops)

 

The coin looked better before you cleaned it.

 

Sorry, don't agree

 

I'm with you, I think. Perhaps I could have lived with the original obverse, but one couldn't even see the design on the reverse, which I believe is vastly improved.

 

Thank you. I'll have to find it and see how it looks now...

 

Wow, what a difference 2 1/2 years makes!!!

 

Well it’s certainly toned back but the details are now really nice. I think this was a great success even after so long.

this way you can’t really see the porous surfaces as well as before

 

I must shamefacedly admit that I also treated it (after the toning) with a linseed oil rub.