Cleaning Coins --- Just when does it start to hurt?

Let's stick to circulated coins here in this discussion because I see than coins in Mint State can not be improved upon and any processing to which the coin is subjected stands a good chance of hurting it.

That being said...How much cleaning can be done to a circulated coin before it becomes damaging to the grade and value?

For instance I've seen copper coins in circulation which have a bit of grease or other soft dirt around the image. If I try to remove it with my finger nail then it comes off. Would a little soap and water hurt this coin? I think not.

Then there is the problem of verdigris. (did I spell that right) Although the damage has been done to the best of my knowledge at least, Would it help the coin if some process were applied to stop further degeneration of the coin with age? I know I have some pieces in my collection which have varying degrees of this problem. They are still the best I can find for the price and effort I am willing to invest. What can I do to stop the continued damage to the coin or should I just do nothing but keep it dry, cool and untouched?

I am sure that I will come up with more possibilities but I hope you see the point I am making.

I know that in "Proper Numismatic Company" we never want to admit that we have cleaned a coin. It is something like questioning the existence of God in Church for coin collectors. As a Christian I know that all of us question our relationship with the Supreme Creator, and I also know that as collectors we have all considered cleaning a coin. I know that at one time I would put that acid on the dateless Buffalo Nickles and it would bring out a date. The coin was worth nothing before I treated it. It is still worth nothing but I did have a lot of fun looking at Buffalos when they were still in circulation using that method.

Just throwing this out because questioning minds want to know. Can we discuss this openly and with civility without fearing the ruination of our reputation in the hobby?

 

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I disagree with this right off of the bat. I'd much rather have to clean an UNC silver or gold coin. Most UNC coins have been dipped at some point or another. If it is done correctly even the grading companies can't tell the difference. I personally don't dip too many coins... but the ones I do are done properly. I'd be much less likely to clean a circulated coin IMHO...

 

The moment originality is affected is when it starts to hurt.

The moment originality is affected is when it starts to hurt.

In other words with knowledge many circ. coins can be improved
by various methods but you must have the knowledge first of what coin are supposed to look like and if this procedure your about to do will adversly effect it. You must also know what a ruined coin looks like and why and how it was ruined and by what method was it ruined. The only way you can get this type knowledge is through experience and looking at thousands, 10's of thousands of coins.
That is why there is such panic when someone asks these type questions. We suspect the person asking has not looked at tens of thousands of coins and a good coin may be ruined.
Plus there is no rush to do this to a coin until you know.
So,,, if you work 30 or more hours a week at coins, you go to shows, look at tens of thousands of coins, ask many people who have knowledge, practice on coins only worth face value and wait about ten years, (five at least) then you to can satrt doing this for yourself.
If I knew any short cut I would tell you, there are none.

 

Would you share some of these cleaning techniques?

 

I'd be glad to after you have done some or most of this.

I'd be glad to after you have done some or most of this.

Plus there is no rush to do this to a coin until you know.
So,,, if you work 30 or more hours a week at coins, you go to shows, look at tens of thousands of coins, ask many people who have knowledge, practice on coins only worth face value and wait about ten years, (five at least) then you to can start doing this for yourself.

Either that or search threads on here regarding same.

 

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Most? Really? And do you have some facts to back this up? If so, please share.

 

OK I admit that was a pretty general statement... not much to back it up except personal experience.

I would be willing to bet that a vast majority of blast white coins in and out of holders have been dipped... Silver tarnishes very quickly...with the proper circumstances I have seen silver coins toned by a coin doctor in as little as 15 minutes... just look at the sterling silverware our grandparents used to keep in anti tarnishing boxes from the 40's and earlier... it's dark and tarnished unless it is polished with the cloth. Coins do the exact same thing so the odds of that blast white coin in your slab or collection being originally blast white are very slim... this is just my educated experience tho.

 

At the risk of unleashing the wrath of all collectors everywhere, I will share my experiences:

First, I have only cleaned very low grade, cull, or heavily circulated copper coins. I have no experience with anything else. I love to purchase cull coppers at extremely low premiums and have been through well over 100k wheats (circulated, cull, and otherwise) Even so, I am FAR from an expert so please regard me as a crazy novice who has no clue what he's talking about

I've found that a bath in warm water will take off a fair amount of dirt by itself. I do this by dumping a few hundred beat up coins in a pot of warm water, letting it sit for a while (a few hours), stirring, rinsing, and repeating as long as the water gets discolored. This has made unreadable coins readable more times than I can remember. Be sure to let air dry afterwards.

For the coins that still are too dirty for my tastes, I'll include baking soda in the pot of water to help loosen dirt, stir, rinse, repeat as above. After the baking soda process I always rinse in clean water, then in alcohol, then let air dry on a soft cloth. This takes time, but IMO is worth it.

For the coins that I still feel need help, I will take a soft toothbrush and rub in a circular pattern to remove dirt. I hate doing this, and will usually only do so until I can make out a date and/or legends. A q-tip also works. Its a long process, especially if you ave a lot of coins to clean. Afterwards I rinse and let air dry. FYI I don't do this on any coin I really care about.

Now for methods I've tried and don't recommend:

An ultrasonic jewelry cleaner - I've used this with plain warm water and baking soda & water. I used a cheapo version but saw no difference between this and just soaking in water and stirring.

Toothpick/dried thorn/other sharp tool - these don't really work to remove the crud thats on my coins unless I'm willing to scratch them :/

Vinegar/lemon juice/other acids - even diluted 20:1 acids always produce a horrible color for me

Soaking in olive oil - while this method HAS worked on some coins, however the process is way too slow for my tastes (months) and has to be combined with the toothbrush method above.

Abrasive rubbing - this method sure gets dirt off quickly but at a definite cost to the surfaces of the coin. Not worth it IMO.

As far as removing verdigris/corrosion nothing I have tried will work without ruining the coin or revealing an extremely unattractive surface. My goal in cleaning coins is only to remove dirt, grime, grease not corrosion or verdigris.

In my process of cleaning coins I have ruined a fair number. I think my worst casuality was a 1909 vdb that might have been a decent filler in someones collection had I not totally removed the natural color. I've ruined a good number of 20 - 30 cents wheaties as well. A few IHCs that I couldn't make out a date on might have made some young numismatist happy before I got to them. I say this because I understand that in my process of cleaning coins I have ruined many as well. I'd like to think that the ones I have cleaned are better off for it though.

Hope this helps, and sorry for any that I offend!

Ben

 

How about if you simply take an old Lincoln cent and soak it in distilled vinegar for 2 or 3 minutes? Not much of a change but it does change the hue a bit and the coin does look cleaner. Would that be enough of a "cleaning" for one of the TPG's to write cleaned on the label? Would that even be considered a cleaning?

 

Yes thanks! Let me be clear. Verdigris if visible has already damaged the coin seriously. Always damage that can not be hidden. ALL I WANT TO DO, is to neutralize it so it goes no further in the ruination process.

 

As far as neutralizing it, I think I remember reading somewhere that you can apply the same oil that gun owners apply to the barrels and that will help with stopping it. Don't do that though until someone else with more knowledge confirms it!

 

I assume you finish it off by using a strong sulphuric acid solution to bring up that "burnished" look on what's left of a coin?

 

I have heard this as well, and I have heard a thin coat of vaseline will achieve the same effect. I have not tried either method.

 

Thanks for sharing your experience trogdor, I do use that method too. Can't say I haven't ruined any coin, because I did. But like you, it was a small percentage. Sometimes a bath in hot water or distilled water can do magic.

 

With the caveat "blast white," this is probably closer to correct--certainly more reasonable--for the reasons you mentioned.

However, I'm still willing to bet that if you conducted an empirical analysis, you'd discover that you are still guilty of egregious over-statement. I could believe 20%, even 40%, but that's still a long way from "vast majority."

If you've ever studied statistics, you already know that the value of "personal experience" is rather limited in this context.

 

I respect your opinion... and you very well may be correct. I was just speaking from my personal experience dealing with some of the larger national dealers of graded coinage. I know more then one major dealer who have special 30 gallon vats built in their buildings just for the purpose of dipping coins and who dip thousands of coins a year. So as you can guess I might be more skeptical...

 

After reading this my mouth open very wide, hand over heart and saying like Fred Sanford, "Elizabeth this is the big one, I'm coming to see you"

 

I think it starts to hurt, when it looks like this after fooling around with it. Traci :goofer:

 

Are you nuts, dont use those.