What can I SAFELY use to clean tarnished coins?

Hi All,

I joined this group because while I was going through old jewelry, yesterday, I found an old Chinese coin that I wanted to find more information on.

That was very successful. Through internet research and with the help of a member of this group, I know pretty much everything about the coin except for the value. That was always secondary anyway, and I will learn that soon enough.

This search spurred me to get out the other old, foreign coins that I have. I got them about 20 years ago, when my grandmother passed away. She was one of 8 or 9 children, and was given them by her brothers, returning from the wars. WWI, WWII and the Korean "Conflict".

I was very disappointed when I retrieved them to find oxidation(?) on some of the nazi coins, heavy tarnish(?) on some of the silver, brass and copper coins, and some of the plated coins looked like there plating had been "eaten" away. Some of the nazi coins had white crusted spots on them.

I'm pretty sure that some type of chemical reaction has occurred as a result of storing all of these metals together in a plastic bag for all these years.

I, of course, now know that this was a horrible mistake, so please refrain from any admonishments. I am just asking for your help and advice in trying to salvage as many of these coins as I can. Can a product like Tarn-X be used safely?

Thank you,
Barry

 

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There is alot of talk about acetone being one of the only safe things to use. But in your particular situation I will let others with experience in this process chime in.

 

if in doubt do NOT clean, acetone is ok to get crusted dirt off coins but the corrosion sots you describe mean that the coins are a bit far gone, and the plastic bag has caused them to become damaged. if they were just stored properly and became tarnished with time then that is called patina, however the way you describe the coins means that they are beyond rescue. if it is just to look at the coins then vinegar is a good cleaner although it will destroy the natural patination and give weird tones to the coins.

 

Absolutely not. Please do not use Tarnex on any of your coins. I can guaranty you that the coins will not benefit from Tarnex.

You may search the word "cleaning" and review some of the past threads on CT.

 

The only completely safe thing you can do is to soak them in distilled water. Distilled water has had its minerals removed, so chemically it is very attractive to many atoms, and they will leave your coin and dissolve into the water. If after a day the water becomes colored it means it is working and you change the water. You can do this many days in a row. When you are done make sure you take the coins out and pat dry them with a cotton towel.

Slightly more aggresive would be to brush them gently while in the distilled water with a hard toothbrush to loosen up the corrosion. That is what you are most likely dealing with, and sorry to say you will probably be looking at damaged coins wehn you are through.

 

Thank you, all, for your advice. I appreciate it, but I've decided to try the most benign treatment first. I will wash them all with warm water, Dawn and a soft cloth.
I honestly have to agree with most of you, that some of them will just wind up scrap.
Oh, well...you learn by living, folks!
Peace,
Barry

 

Thanks GD,
The Dawn helped to clean the copper, but didn't have any effect on the silver, brass and zinc. The last time that I looked at these coins was around 1980, so I don't know how long they've been this way, but since I do know, now, I have to do what I can.
I'll save the ones I can, sell them with open disclosure of the cleaning and put the rest of them away. I know that the ones that aren't aesthetically salavageable don't have any monetary value, but they still possess sentimental value, so I can't just throw them out. Thank you, GD, you have a fine group here.
Peace,
Barry
BTW-I noticed that you are in Florida. I spent the last 21 years in Key West and I sure wish I was back there now!

 

Barry,

Just to let you know, any detergent is potentially bad for coins as it can promote bronze disease. If you washed these in Dawn you should do the soak in distilled water like I said for a few days. I have seen what detergent residue can do to coins, and it is severe.

 

Thanks, Medoraman,
They are all soaking in water now. I'll get some distilled water tomorrow, but the water they are in now is from my Brita pitcher. At least there's no chlorine in it, LOL. Tomorrow I will be trying the acetone on the really bad ones to see what happens. I'll keep you all advised so that if any other "newbies" come across the same problem will know what NOT to do.
Have a Great Evening, Friends!
Peace,
Barry

 

The OP specifically mentioned problems with Nazi coins and I suspect that the coins in question are those zinc things that tend to look beyond terrible. I don't collect these things but have been asked by more than one person over the years and would really like to know what can be done to help them.

Coin cleaning is very much a matter of opinion. If you ever expect to sell the coins, it would be best to have the same opinion as most people in the market for the type coin you have. That means no cleaning in many cases and lighter cleaning when the thing is caked with 3D dirt or is uneven to a point of being offensive. Rules vary for high grade 20th century coins and for metal detector finds from 200 to 2000 years old. We will differ on what is allowable and advisable depending on what we want to achieve. I once saw a $1000+ encrusted ancient rarity being carried as a pocket piece by a dealer along with dozens of modern coins. His theory was that the wear of the process would produce more natural looking effects than anything he could do directly. In ancients, a high eye appeal VG coin can be worth more than a scabby VF with raw surfaces. I always wondered what happened to that coin and if he stopped the process when it was looking good.