Dipping MS and Proof coins

The biggest issue I have found dipping silver is the high risk of killing the luster. I had a Maine commen that had some weird and ugly tanic toning but still decent cartwheel luster. It was in a PCGS 63 holder. After talking it over with a dealer who said he would dip it in a second and would be able to get it in a 64 holder, I tried it.

I bought the tongs, had the distilled water, cotton gloves, and soft cotton cloths. I followed his advice which was to dip the coin very quickly using the tongs. I then rinsed and dabbed with the cotton cloth. The ugly toning came off pretty quick (some still remained though), but so did most of the luster. The coin was much more dull and lifeless. The dealer who advised me about this thought it was still a 63 (which I agreed with, but it was a lower 63 than before) and bought it from me as such.

Since then, I have put an occasional copper coin into acetone with good results, but that is about it. I learned my lesson with silver.

I hear some people are really good at dipping silver...I am not one of them. I would advise against it unless you are willing to roll the dice.

 

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You might be right. Or not. I don't know.

Can't condemn them as "egregious" when one thinks something might happen.

 

This will always be a touchy subject. I have no expertise on dipping, so I'm just gonna stay in the "don't touch it" crowd.

 

Now you know. It can be both good and bad, much like NitroGlycerine; in one use it will save you from having a Heart Attack, but just don't drop the pill...

Ben

 

How many milligrams are those, makes a big difference...

Ben

 

I've shot nitro pills against a tile wall with a slingshot and beat them on an anvil with a 3 pound sledge, just to see what would happen.

They just shattered into powder

 

for the love of god peter give me a ban button

 

Thanks. I learned something. Not the nytro pills thing..(I'll ask that question when I when I become an old geezer).

 

Yes, it is an 'uncomfortable & unmentionable' little secret the TPGs have.


Bne

 

As opposed to dipping a coin, which could be damaging, someone here at coin talk mentioned a coin detergent called MS 70. This is supposedly in and of itself not damaging to gold, silver, nickel, and copper; however, there is a warning on the bottle that you should experiment with copper coins before using it on something important.
I'm sure this is due to the fact that copper coins can really look strange when the tarnish/ oxidation patina is removed.
Anyways... I bought some of this stuff and tried it out on some AU common pre-1933 gold.
3 of these coins had a high AU grade, but not much luster. 2 of the coins looked as though they may have been improperly cleaned in the past, and they also did not have much luster. All of the coins had small amounts of black residue around the rim, or on the shield on the reverse. For the most part they were all decent looking coins with very little wear. I used the ANA grading standards on these gold liberty 2.5/ 5/ 10 Eagles, and the wear is barley detectable except for on 2 of the coins which like I said may have been improperly cleaned by someone in the past.
Ok MS 70 says this solution is not a dip, and that dipping the coin in MS 70 will not work "like a dip". The instructions basically say to cover one surface at a time, wait a few seconds, and then agitate the solution on the surface of the coin with a Q-tip. When finished wash the coin with water, and blot dry. So, I covered one side at a time with the detergent, waited a few seconds, and then I basically just rolled the Q-tip over the surface of the coins without "scrubbing", or moving back and forth. I did this just in case a cotton Q-tip could actually create hairline on a gold coin. After examining the coins post MS 70 procedure, I do not think a Q-tip can be damaging in and of itself, and I also don't think that MS 70 or the procedure damaged any of the coins.
The AU coins all look much more apealing as their luster has been restored, and any dirt or discoloration is no longer present. In fact one of the reasons I would have bumped these coins down to AU is because the gold was discolored where someone may have touched it or run their finger over the coin. Often coins get AU 58 because of detectable rub, but would otherwise be MS coins. This fingering, or rub leaves a presence that is detectbale, but after using MS 70 it would be impossible (for me) to know this was there beforehand. 2 of these coins I would call MS if I were looking at them for the first time. The other has a little bit of wear or maybe a weak strike, but I cannot honestly say it would make an MS grade.
As for the two coins that may have been improperly cleaned the first is an $10 1880 Liberty Head Eagle that I got for $460, which is barely over the bullion value. It was much more obvious after using MS 70 that this was a problem coin. Before using MS 70 under 10x magnification this coin was not pretty, but had AU details. After using MS 70 the AU details were still present, but it is now glaringly obvios someone had went to town on the obverse. The fields, and Ms. Liberty's face are scratched badly and IMO the MS 70 procedure just made what was already there visable to the naked eye. The other coin in question just has quite a bit of visible hairlines in the fields and this seems to be common even in MS gold. It may have been cleaned in the past I don't really know, or can't tell. It is a nice looking coin and the appearance was improved.
So although I did not dip the coins or damage the coins they were "cleaned" in a a non damaging way. I haven't tried it on silver, copper or nickel, but I would say this product/ procedure is a positave thing for gold; however, the coin's true state will be "exposed". If you have a problem coin it will look more problematic. If you have a nice coin, it will probably look nicer, as the luster will be restored.

 

Is luster ever really gone then, or just hidden? Gold is a lustrous metal, and with the exception of sodium chloride, or bromides I do not know what would actually effect gold.
Since most gold coins are alloyed with copper, I guess the "tarnished" look is really from the deposition of metallic ions (mainly iron). So according to you these "detergents" only remove particles exposing what already exits?

I think you are right about the Q-tip; however, I think you would have to go a little overboard on the elbow grease to scratch even a gold coin with a Q-tip. MS 70 almost feels like a lubricant which also diminishes this risk IMO.

FYI I am not suggesting the use of MS 70 to anyone, but as for me I would use it before dipping. I have heard from GDJMSP and others that heavy tarnish is much more difficult to remove with MS 70.

 

what about that 99.999%gold coin i would like to think those would not tone along with platinum

 

The whole post was great. Good information to know. Thank You.

 

What's their rationale for keeping it a secret?

 

because of the "stigma and taboo" of "cleaning" coins