Dipping MS and Proof coins

I've known dealers that dip MS coins, just briefly to remove tarnish and unappealing toning. No scrubbing involved just a quick dip followed by a rinse in extremely hot water, then blotted dry with a cotton cloth. My question is: is this safe for proof coins as well?

 

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Nope. Dipping coins is a gamble. While it is possible to dip a coin without destroying the surfaces, it takes a LOT of practice and know-how, and even then it takes a fair amount of luck.

I know a dealer who dilutes the dip solution and then does a really quick dip and rinse, but only for heavily tarnished coins, and only where he thinks there's a good shot at increasing the coin's value.

Even for him, with 20+ years of experience, it's a gamble, because even these really quick dips are cumulative, meaning that he doesn't know whether or not the last person that owned it gave it a "quick dip" years ago, etc., and eventually, even "real quick dips" by experts will have enough of a cumulative effect on a coin's surfaces to show signs of cleaning.

And that doesn't even scratch the surface (no pun intended) of things that could go wrong when you try to dip a coin. Add in the extremely fragile nature of the fields on a proof coin, and you're just asking for trouble.

Just my 2 cents, but dipping coins is a huge gamble, and you're waaaaayyyy more likely to ruin the coin than you are to help it.

 

I'm not experienced in coin conservation, but I would like to find a book on it.

Logic would lead me to believe that anything you could do to damage an MS coin would only be amplified 100 fold on a proof coin. Any tiny alteration on a proof coin is going to be much more noticable and possibly very destracting.

I had a thread on Cleaning/ Conserving gold coins and the majority of responses were DON'T TOUCH IT, and for good reasons.

There is a difference between conservation, and destructive cleaning, but you aren't going to find out much here.

I talk a lot about risk vs. reward because the scales of justice are constantly teetering to and fro. If you make the wrong move you fall into the reality of consequence.

 

I read an article about this multiple dipping effect, and it can end up to seriously damage a coin's surface.

I have not tried it but there are also some detergent solutions out there that are non-destructive. They are more geared towards removing foreign particles on the coin's surface than changing the tone or enhancing luster. You still kind of gamble when you do this because dirt, grime, buildup, et cetera could be hiding something far worse than just dirt like a little pit, or gouge.

I think you also need to consider the metal content of the coin. Some metals are more prone to problems like copper. Do you really want to remove dirt from copper????? If you dip it the unatural color would be noticeable to even a novice.

Gold is the least likely to corrode in any kind of way so there would probably be less problems to find behind dirt, but sometimes it would seem gold coin surfaces are much more telling of a tooling hand. I have seen so many gold coins with shadowy, milky, uneavened in color, and altogether strangel looking surfaces. Someone probably did something to make it nicer?

I go to Vegas every year so I know what it is like to lose money. If your OK with that too, try it out. I'm sure everyone would like to learn from you without having to do it themselves. I know I would. haha

 

I've read here (posted by respected members) that TPGs sometimes dip coins before grading and encapsulating them as well.

 

I had a question about that and some CoinTalk folks confirmed that to me as well. This is a great place to learn!

 

There is no such thing as a "safe" dip. That said, dipping proof coins is less problematic than dipping MS ones.

 

Why is that, Leadfoot?

 

Is ultrasonic cleaning included in the concept of dipping? It seems to me that if you just want to clean (i.e., remove dirt) a coin then ultrasonic cleaning shouldn't damage it. No chemicals would be involved. Would microscopic bubble cavitation damage the coin's surface?

 

Ultrasonic jewelry cleaners use sound to vibrate the object at a high frequency. It is supposed to shake dirt free, but they also use a detergent solution. I would think this would work if the coin was on a soft surface that would not be damaging to the coin. But really you never know whether the surface of the coin would be affected because of what the coin would be touching while it was vibrated?????

 

What did they use on the coins recovered from shipwrecks , these coins were heavily tarnished or encrusted yet some coins are among the highest graded by tpg either PCGS or NGC .
rzage

 

When dipping proof coins there is a greater margin for error because there's not as much luster to burn off.

Regardless, it is easy to make a mistake and overdip a coin. Neither can you always predict the dip will give you the results you expect.

It's a gamble.

 

I spent a year at PCGS, and I'm confident this did not happen there (while I was there anyway). I'm not sure about the other TPG's though.

As far as dipping goes, it really takes a trained eye to predict how a coin will dip, and even then you get a few that go haywire.

 

That seems a bit of a gamble Bone. I mean why would they do that? and if they do do they claim ''cleaned'' after the grading? HaHa. As for the shipwrecked silver coins; they do use something to remove the dirt but not the damage caused by salt water.

 

Be very cautious about using the 'cleaner' that is sold with ultrasonic jewelry cleaning machines.
I know for a fact that sterling silver jewelry will clean beautifully and may stay that way for a very short time, but sooner or later it will oxidize into very black silver.
jeankay

 

Sorry I guess I should have specified I was talking about silver MS and proof coins only, copper and cu-ni are just to much of a gamble to dip.

 

Ok. Thanks. Let me ask this; If by some miracle I ''properly'' dipped a coin and told a TPG service I did. Would they consider it ''cleaned'' then? I'm thinking they would. And that seems a bit egregious somehow.

 

Re: And proper dipping of a coin is not considered to be cleaning by most in the hobby.

How DO you define the conditions for "proper" dipping?

I hear all kinds of different opinions here. I have occasionally dipped (quickly) less-valuable uncirculated coins to get the "haze" off, before I put them in 2x2s (mostly State quarters). I have rinsed dirty coins in hot, distilled water, then either patted them dry (lightly) with a soft cloth, or let them air-dry. But I admit to being a bit confused on this subject.