Dipping MS and Proof coins

Ultrasonic cleaning is included in conservation. Their are many different commercial solutions and some make their own "secret juice." The solutions range from tap water to beyond...

Unless you know what you are doing, even the "rig" holding the coin may damage the coin as it vibrates... and YES, if a bubble gets attached to one spot of the coin it will start to bore a hole into the surface

And you don't want the coin touching ANY SURFACE. Plastic tongs seem to work best.

 

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That is a proprietary secret at NCS. I've tried to find out many times Unless you can get one of them to talk and risk loosing their job - who knows. PCGS has said a little about what they did to the salvage coins but I've forgotten what I read and where. Look up sea water conservation of coins and in many cases electrolytic baths are mentioned. Anyway, the encrustations on gold are easy to remove. Remember, gold is impervious to most acids while the crust is not. Salvaged silver is a much different story. Most of that stuff is corroded so the term "sea water surface" or something similar is put on the label.

 

Nuts and Myth. IMO this fella has not dipped enough coins properly OR has ruined lots of coins.

 

As all silver does. Conservation, dipping , cleaning, whatever strips any surface that has developed (good or bad) from the metal and exposes it to new forms of "deterioration." That's why coins that have "set" and developed attractive "skin" or patina are sought after.

 

Again, unless you know what you are doing. It's a shame we cannot pay a TPGS to let us watch them conserve coins for a week. That should end much of the uninformed posts and opinions around here.

JUST AS THERE ARE NO SECRETS TO AUTHENTICATION OR GRADING; THERE ARE NO SECRETS TO CONSERVATION in this age of the Internet. I know at least three dealers who were self taught that could work at ANY TPGS conservation lab.

A month ago at a coin shop I showed another dealer some of the "cleaning tricks" I know to conserve coins as he considers himself a novice. One week later, he calls to tell me he "discovered" a brand new method on his own! All it takes is a desire, access to a bunch of coins, some chemicals, and a computer to "play."

 

Easy...No one can tell that the coin is not in its original, unaltered condition. So Uncirculated coins look as if they were just made and circulated coins look natural. Overall, the piece looks better than it did before treatment and no harm to the coin or evidence of conservation is present.

 

Much of the damage to a coin that is cleaned happens when it is being dried. Never let a coin "air dry" either. Now you do some research on your own and post some answers for us: "How to properly dry a coin."

 

This is the typical advice we all get. Unfortunately, doing the job right is much more complicated. Truth be told, after deciding the coin is a suitable candidate for conservation, professional conservators may go through SEVERAL steps prior to dipping a coin.

 

Doug and I have a disagreement on the term "Luster." All surfaces have luster, even wood or plastic. So let's keep the subject limited to the luster from a metal surface like a coin.

Most metal coins have some type of luster caused by the reflection of light from their surface. So let's keep the subject limited to the MINT LUSTER found on a freshly made coin. AGREED?

So the LUSTER ON A COIN IS NEVER REALLY GONE, in fact the luster from a polished coin or cleaned coin is often more intense, brighter than that of an original piece; however that is NOT THE SAME type/quality/appearance of ORIGINAL MINT LUSTER. Therefor the luster may not be gone but the original mint luster is gone forever.

Again, the luster of a coin can be restored (polish, whizzing, etc) BUT IT IS NOT THE SAME as the original mint luster.

I think Doug and I can agree on my comments.

 

This is absolutely NOT TRUE as can be/has been proven in class experiments.

 

It is not the Q-tip. It is the risk of dislodging a hard particle that can hairline the coin. MS-70, Verti-Care, Care, even soapy water are lubricants that can minimize the risk of hairlines. Never rub a Q-tip across a surface - roll it when it is heavily saturated w/chem.

 

I cannot believe you punctuate your considerable wisdom with utterly misleading statements like this.

People, thiourea is acid. How long can you soak something in acid? Every coin whose luster I've ever deliberately removed with dip (yes, luster is a hobby-specific term with exact meaning despite what's tossed around here about wood having luster; perhaps it does but it isn't numismatic luster) has taken less than 15 seconds. And since the effect is cumulative, how long can you dip a coin which has already spent 10 seconds in dip?

Why do you do this, insider? Are you truly so malicious you want people to destroy their coins?

 

Tough to agree with that. Please tell us more.

 

If you have to dilute dip to use it, chances are you shouldn't be using it. Thiourea is - as you know, of course - a solution to one single problem: toning you don't like, when you don't care enough about preserving the coin to achieve the removal without violent intervention.

 

I couldn't wait to get on CT today - I need some humor dealing with the "ex-perts" here....Now, why don't you do some experiments before MOUTHING OFF? A bunch of you people here are spouting myths about dip and how to use it.

I've had a clad proof dime sitting in dip on my desk for a while. Finally the mirror is gone (I won't say how long it took NOW because of the crap I'm reading today) BUT DO YOU KNOW WHAT? The coin now looks like A MATTE PROOF. So, all you experts who say you can RUIN THE MIRROR SURFACE on a proof are correct...WAS THERE ANY DOUBT - dah? Many (NOT ALL) chemical dips are acid - Dah. However the coin still has all the characteristics of a Proof (except the mirrors) and the coin was soaking for longer than 2-3 seconds!

Now, go to your "lab" with an original silver coin and start dipping it. You'll get light headed and exhausted before you ruin the coin Then, you can write that perhaps you were not as smart as you thought

 

I want everyone to be exposed to useful numismatic knowledge. I've been lucky to know/been taught by/and experimented with several numismatists and conservation specialists in my LONG CAREER

 

Too bad you haven't learned anything during all that LONG CAREER.

Readers, thiourea - "dip" - is ACID. It works by stripping molecules of metal off the surface. You cannot just "leave coins sitting in it." Use your heads, folks. Does it make sense that you can leave stuff soak in acid? Didn't think so.

 

Idhair, this is not directed to you - just an answer to your question.
Curiosity is good and so is proof.

I have done many, many experiments using different chemicals on coins of different compositions. In two seminars long ago we did the experiments with dip and luster. Dip - look Dip - look on an on. Using a control coin there is no detectible difference in luster after ______ of dips. You'll get no more info from me on this because WHAT DO I KNOW? I'm just a stir-up, ignorant .

If you wish to learn something. Try it yourself.

BTW, This entire "DIP NO GOOD it changes luster" started in the 1970's or early 1980's when a respected numismatist taught this nonsense. I learned who he was and what he did in at an ANA Summer Seminar decades ago!

The "Expert" took a commemorative half over to a window, put a light meter on it and took a reading. Then he dipped the coin and took another reading that showed a decrease in reflectivity (luster). My instructor told us THAT A CLOUD MUST HAVE PASSED IN FRONT OF THE SUN during the second reading Then we did the experiment with dip and proper methods /when to use it.

Until you guys do some tests for yourself...

Finally, in some cases even a professional CAN RUIN A COIN'S LUSTER with JUST ONE dip so...Learn what coins to conserve (some will still blow up) or don't touch your coins. AND...Quit commenting on subjects that IMO you know TOO little about! (red & green look good together).

Good Day