Can you tell if a coin has been dipped?

dwood · February 21, 2003 2:13AM

Just by looking at a coin, or picture of a coin, is it possible to tell if it has been dipped?

DanC · February 21, 2003 2:14AM

If it's done badly even a nubie like me can...

Baley · February 21, 2003 2:14AM

sometimes, sometimes not. depends on the coin.

post a pic, or better yet, send me a coin and you'll get my opinion, which may or may not differ from yours or anyone elses.

edited for grammar

dwood · February 21, 2003 2:18AM

I'm not talking about a specific coin. Its a hypothetical.

nwcs · February 21, 2003 2:20AM

Yes, with increasing ease with successive dippings or concentration of dip solution. But when very light and diluted, can only be seen microscopically.

Baley · February 21, 2003 2:23AM

then do you mean is it Always possible to tell?

then, no, it's not.

and neither is it Never possible to tell.

it depends.

remumc · February 21, 2003 2:25AM

So what is it that you look for to tell if a coin has been dipped? It may be great that you guys can tell, but we need you to teach those of us who don't know, how to tell & what to look for.

Tegards,

Wayne

dwood · February 21, 2003 2:26AM

Yes, what are the signs? I know it gets increasingly worse with successive dippings, but what is it you look for if a coin has been dipped once (and done very well)?

dorkkarl · February 21, 2003 2:32AM

in many cases, the answer is "yes". the secret? look at the rim 1st. assuming most dipped coins came out of either albums or rolls, the rims tone darker, sometimes much darker than the obv & rev. obviously, they will lighten to a lesser extent than the surfaces, which presumably started out w/ less toning.

coins in slabs - obvious problem. you now understand 1 reason why i crack all my coins out.

hint #2: typically, you look at the surface of a coin dead-on, ie. at a 90 degree angle. try looking at the surface at a very oblique angle, w/ brilliant light shining essentially right at you. compare the light diffusion betwen a coin you know for a fact to be undipped, & 1 that has just been dipped. again, this is near-impossible while a coin is still in the slab, the plastic distorts the angle of light.

these are just 2 factors to look for, plenty of others are available. these 2 will go a long way though. but i would venture to guess there is no definitive litmus test, other than observation at the molecular level.

K S

nwcs · February 21, 2003 2:33AM

Well, since the question was theoretical, the answer involves some theory. A dip is an acid solution. It strips away some metal on the coin surface. No matter how well done or anything, it must leave a trace because its very nature is a changing of the surface. How easily detectible is another matter. So in theory it can be detected, in practicality maybe not. Especially if you do not have before images.

Baley · February 21, 2003 2:35AM

ok, you suspect it's been dipped, so it must be pure white, right?
(lets assume we're talking silver coins here; dipped copper is much easier to spot. I guess we're also talking mint state silver, because dipped circulated silver is obvious too)

OK, look at the date. is it before 1950? the chance it's been dipped just went up.

is there no color variation at all? is it a uniform white without any toning whatsoever, even in between the reeds of the edge? the probability of it being dipped is increased.

ok, now rotate the coin in a good light, and look for luster. is it frosty or kinda smoothy? if it's subdued (and here comparison with a known undipped and very lusterous coin of the same type and era may help) then it may be dipped.

now *gently* feel of the edges and rims... do the feel kinda "squeaky"?? probably dipped.

well, that's a start. it's still not possible to prove anything, you can only go on probabilities.

DanC · February 21, 2003 2:37AM

Russ has got some pretty decent photographic examples of bad dips.

Bear in mind, I've looked only at proof coins as examples - but have seen some really lousy jobs on coins I've bought.

Alot of times, you can see "drip marks" or what looks like dried liquid on the mirrors - very nasty.
Over-dipped seems to result in an overall loss of luster, as the surfaces would become etched and equally nasty.

It can be done carefully, in a conservation way (I've seen it) but - I would never dare to dip a coin personally - just too risky, and I don't know enough to do it without damage.

dwood · February 21, 2003 2:39AM

Hmmmm....

It'
s very interesting.

Steve27 · February 21, 2003 2:39AM

No.

coinguy1 · February 21, 2003 2:41AM

If a coin has been properly dipped and rinsed/neutralized, it is unlikely you will be able to tell, no matter how high your level of expertise.

If it has been over dipped, the luster and "original skin" is partly lost.

If it has been improperly rinsed/neutralized, it might show evidence of retoning (often light golden color, that can turn to darker gold, and eventually brown or blue, among other colors). Sometimes this occurs very quickly, while other times it's a more gradual process.

If it was deeply toned, sometimes not all of the toning comes off and you will see isolated patches or areas of toning remnants/stains. For proof coins, the result is often white-colored toning remnants/stains. I have, unfortunately, seen this on many high grade (even PF 68) 19th and 20th century type coins, that sell for five figure prices.

Blackhawk · February 21, 2003 2:46AM

It's easy to tell if the coin shows wear. If the coin is BU and has been dipped properly, it's almost impossible. Only certain lighter toning can be dipped off a coin without leaving evidence of the treatment. Very dark toned coins will almost always come out of a dipping with poor lustre.

Dog97 · February 21, 2003 2:50AM

Read all the Dog97 replies to this thread: Text

ah · February 21, 2003 2:53AM

It depends on the Doctors expertise and the Quality control he uses.

dwood · February 21, 2003 2:54AM

Going a little deeper....

If you took an accurate photo of a Mint Sate coin showing no need of dipping, then dipped it following "safe and proper" guidelines, took another accurate photo of the dipped coin, then compared the two photos, could you notice a difference? Would the luster be diminished at all (though still probably beautifully lustrous, would it be slightly less than prior to the dipping?)

Baley · February 21, 2003 2:55AM

well, why doesn't *someone* do the experiment and post the pics here?

dwood · February 21, 2003 2:56AM

Even more interesting Dog...thanks for the link!

dorkkarl · February 21, 2003 2:57AM

photo, or digital photo? digi-pic's - no way.

K S

Baley · February 21, 2003 2:57AM

I'm about to crack
<------this coin
out of it's PCGS tomb and dip it overnight, so I'll post the "after" pic tomorrow morning...

dwood · February 21, 2003 2:57AM

photo....as in film....as in REAL photography

dwood · February 21, 2003 2:58AM

Baley, that would be swell. Thanks!

dorkkarl · February 21, 2003 3:03AM

baley, you'd better not be serious!!!

K S

Baley · February 21, 2003 3:06AM

oh, did I forget the emoticon??

here you go...

billiardmaster · February 21, 2003 3:07AM

Pretty easy to tell if a coin has been dipped. You don't pick up the art of coin grading from a book or one class. This takes years. Or at
least you have to see thousands of coins. Some never do understand what to look for. Just the truth.
Rusty

dwood · February 21, 2003 3:11AM

But back to my last question...Could you tell the difference between the photos of the original BU coin and the "just properly dipped one?" Wouldn't the luster be slightly different at least?

crito · February 21, 2003 3:29AM

If the toning is deep and splotchy, there will be "flat" areas (as in look/luster, not physically flat) after the dip. You can sometimes see them with the naked eye by view coin at a sharp angle to a bright light (like sunlight). If the coin only had haze or light even toning, you won't be able to tell even with a 16x loop.

My general rule is: The deeper the toning and the more delicate the surfaces, the riskier a dip becomes. Light and even gold toning on a satiny surfaced coin is a lot safer to remove than, say, deep splotchy toning on a proof. You can ruin a coin with only one dip.... especially if you dip it overnight... YIKES!!! You're scaring me

P.S. If you do happen to leave a silver coin in a sulphuric acid dip overnight, BTW, you'll find particles of silver on the bottom in the morning. If you then dip a nickel in the same solution, the silver particles will be attracted to and stick to the surface of the coin. That's how I accidentally figured out where all these "light rainbow" nickels were coming from

How many would you like?

MacCoin · February 21, 2003 3:35AM

if the luster is washed out of the coin I can tell. for me proof seem to show more.

dwood · February 21, 2003 3:38AM

Crito,
I'd like one, or two

dorkkarl · February 21, 2003 3:41AM

crito, give copper-sulphate a shot sometime.

K S

Dog97 · February 21, 2003 3:45AM

dwood asks: Could you tell the difference between the photos of the original BU coin and the "just properly dipped one?"
The answer is no.

dwood · February 21, 2003 3:51AM

So then the dipping solution doesn't affect silver at all? Only the compounds that result in the toning? (I have absoilutely no experience with dipping, so I'm asking in complete sincerity).

Then it would seem to me that if Baley leaves his coins in the dip overnight, there wouldn't be any noticeable difference than if he removed them immediately after the last of the toning was removed?

What is an industry accepted dipping solution, and where can I buy it? I'd like to perform a little experiment.

dorkkarl · February 21, 2003 3:53AM

water is available at the nearest kitchen sink.

K S

Dog97 · February 21, 2003 3:56AM

My comments on the "just properly dipped one" do not apply to Baley leaving his coins in the dip overnight.
In Baley's case, yes, there will be an easily seen difference. The coin will now be a dull gray ghost.

ccr · February 21, 2003 4:01AM

Here`s an example of a `23 Peace dollar that has been dipped. Maybe it was dumb luck that I picked up or it was just a really bad rinse. Whatever the reason, you can see two dried up drops, one inbetween the 2 and 3, the other is inbetween the 9 and 2. Also when I have it in my hand, there`s a heavy milky film when you look at it in adequate lighting and looking at it in different angles. On the reverse, under the same or similar lighting, a regular lamp light bulb, moving it around at different angles I can see where there use to be some heavy and dark toning that is still present. It`s faint and didn`t notice head-on until one day I was looking at it in different angles and it popped out at me.

dwood · February 21, 2003 4:01AM

Dog...what's a good dipping solution? (One that is widely used among reputable dealers and collectors)

crito · February 21, 2003 4:03AM

I'm almost afraid to reply dwood

after all the treads on what's "AT", what's "doctoring", what "is" is, etc

I guess that depends on the definition of "dip" and "dipping". There used to be a guy here, MrDQ (he owns a dairy queen), who dipped a Walker half in chocolate. For most people though, "dipping" involves and acid, which does remove some silver, very slowly, but removes toning almost instantaneously. So the amount of time a coin spends in the dip solution is critical (as well as the strength of the solution).

dwood · February 21, 2003 4:45AM

I'm gathering that "dipping solutions" are a lot like barbeque sauce, in that everyone has their own recipe?

Anyone care to share theirs?

Dog97 · February 21, 2003 5:07AM

ccr-
Everybody knows that I'm super critical of coins, mine & everybody elses, but I wouldn't be so fast to condem your coin. I really don't see any traces of the dipping, at least from your pict anyway. The white spots are water spots and they are from poor planchet preping as is the milky haze you mention. I do see a brownish tint that's consistant with dipping along the periph, especially at LIBE but that's probably the lighting.

A good dip is JeweLuster, available in the coin section of eBay.

remumc · February 21, 2003 5:24AM

If using JeweLuster, what would be the average "dip" time? I'm talking about a coin with say, a light film of ugly brownish toning, probably a result of a previous dipping. Aside from rinsing, I would assume with distilled water to prevent mineral deposits, what is done to neutralize the "dip"? If the dip is a mild acid, wouldn't you need to neutralize it with a mild base? Then how do you neutralize the base? Sounds like a no win situation to me!

Regards,

Wayne

LucyBop · February 21, 2003 5:24AM

Who put the Dip in the Dip Dit Dip Da Dip!

Who was that man. I'd like to shake his hand, he made my baby fall in love with me.....

dwood · February 21, 2003 5:29AM

Ok,
I'm wondering what coin(s) to use for my experiment. I'm thinking I'll need 3-4 for all the things I want to look at.....

Then he got an idea...
An awful idea...
dwood got a wonderful, awful idea!

FRANKLINS!!!!!

<ducking>

LucyBop · February 21, 2003 5:31AM

dwood you fiend!!!!! Ban him, ban him ban him Ban him, ban him ban him
Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him
Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him
Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him
Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him Ban him, ban him ban him

GO SOAK A PENNY! NERD!

dwood · February 21, 2003 5:33AM

ROTFL!!!!

Ok, Ok....I'll use Carvers

<ducking again>

dwood · February 21, 2003 5:37AM

Actually, I'm really thinkjing of doing this. I'm going to be near a coin shop tomorrow, so I might try and pick up some cheap Morgans and SAEs, then pick up 3-4 "popular" dipping solutions and give it a whirl. I can hook up the webcam (I have plenty of web space) and let everyone suggest experiments and see the results.

Sound like fun? Or would I be going to a bunch of trouble just for myself?

remumc · February 21, 2003 5:39AM

dwood,

You're on the right track, but an even bigger coin would work better, how about ASE's?

Regards,

Wayne

Dog97 · February 21, 2003 5:42AM

Let me tell you guys something; very few coins are actually improved from the dip and most are forever ruined, especially if they have dark tone on them. Dip it in and pull it out as fast as you can and rinse quickly. But you'll take a dark coin dip it, look at it, hmmm didn't much happen, dip it again, look at it, hmmm didn't much happen, dip it again, hold in the dip a little longer this time, look at it, hmmm got a little lighter, dip it, swish it around for a little while this time, BOOM!! YOU DONE RUINED IT!!

coinguy1 · February 21, 2003 5:46AM

dwood, you said :

"ROTFL!!!!

Ok, Ok....I'll use Carvers"

On behalf of Sir Clankeye -

Can you tell if a coin has been dipped?

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