A question of the science behind luster & dipping
BryceM
Posts: 11,843 ✭✭✭✭✭
So, I've seen "facts", even more "opinions," and perhaps still even more ideas parroted from some other place pertaining to this topic and I'm here to dredge it up again. 
Actually, I'm trying to learn something. It pretty clear to me that luster is the surface quality most easily lost by poor treatment, corrosion, or other mishandling of a coin's surfaces. Luster, it seems, is imparted to the coin during the striking process by metal flow. This metal flow occurs in reproducible, predictable repeating microscopic parallel lines. Brand new dies with fewer surface imperfections impart less luster than old, worn dies. Highly polished dies, as would be used for proofs, actually impart no luster. Am I OK so far?
Corrosion, tarnish (this is for you Rick), or "toning" is due to various chemical reactions that take place between the coin itself and impurities from fingers, albums, the atmosphere, or storage containers. With respect to silver, the most important of these is sulfur, and sulfur-containing compounds. Still OK? Accumulate enough of this and a once brilliant coin can be hidden behind a gradually darkening layer of patina. An interesting effect can take place with respect to the thickness of said contamination layer and its difraction of light. In certain situations, this effect is responsible for the pretty colors so commonly seen (and desired) on Morgans, Franklins, and a few other series. In other situations ugly yellow, brown, black, or uneven splotchiness happens. Still OK?
Dipping is the application of a variety of substances with the intent of removing undesirable tarnish to reveal the pretty coin underneath. I think it's a foregone conclusion that the majority of 150+ year-old coins have seen a dip bucket at one time or another. It's pretty clear that a boatload of numismatic and bullion-quality coins are subjected regularly to dipping, even in our curent enlightened era. It's also pretty clear that the composition or harshness of various dips has been less than standard through the ages of our modern hobby.
OK, now for the part I want to learn about......
For the sake of argument, let's assume we intend to dip a coin with a certain ubiquitous modern product that is sold in little cylindrical white and blue containers. In doing so, even a non-numismatist can see that a dark coin becomes brighter almost immediately. Which of the following statements is most true?
1) The dip solution removes silver-sulfur compounds, leaving whatever is left of the coin intact. If the corrosion was severe enough, surface irregularities responsible for luster were already lost and the coin now has a "lackluster" appearance. If the corrosion wasn't that deep, there is plenty of the original surface irregularity intact and that coin will retain whatever luster it still had, partially-hidden though it was by the toning.
2) The dip solution indescriminately removes a portion of the coin's surface. A quick dip will remove only the tarnish while an extensive dip will dig a little deeper, affecting the surface to the point that luster is lost.
I'm of the opinion that a dip will do nothing to change a coin's luster. Either luster was there before the coin was dipped (possibly hidden by the toning) or it had already been lost and the dip only revealed the already-damaged surface that was waiting to be discovered.
For the record, I think dipping is 95% bad, 5% good. Once a coin's original patina is gone, it's gone forever. A coin can never be "un-dipped". However, some coins can be rescued from PVC, previous poor attempts at "conservation", corrosion that is getting a little too far advanced, or toning that is just plain ugly to everyone who sees it.
What say you?
Actually, I'm trying to learn something. It pretty clear to me that luster is the surface quality most easily lost by poor treatment, corrosion, or other mishandling of a coin's surfaces. Luster, it seems, is imparted to the coin during the striking process by metal flow. This metal flow occurs in reproducible, predictable repeating microscopic parallel lines. Brand new dies with fewer surface imperfections impart less luster than old, worn dies. Highly polished dies, as would be used for proofs, actually impart no luster. Am I OK so far?
Corrosion, tarnish (this is for you Rick), or "toning" is due to various chemical reactions that take place between the coin itself and impurities from fingers, albums, the atmosphere, or storage containers. With respect to silver, the most important of these is sulfur, and sulfur-containing compounds. Still OK? Accumulate enough of this and a once brilliant coin can be hidden behind a gradually darkening layer of patina. An interesting effect can take place with respect to the thickness of said contamination layer and its difraction of light. In certain situations, this effect is responsible for the pretty colors so commonly seen (and desired) on Morgans, Franklins, and a few other series. In other situations ugly yellow, brown, black, or uneven splotchiness happens. Still OK?
Dipping is the application of a variety of substances with the intent of removing undesirable tarnish to reveal the pretty coin underneath. I think it's a foregone conclusion that the majority of 150+ year-old coins have seen a dip bucket at one time or another. It's pretty clear that a boatload of numismatic and bullion-quality coins are subjected regularly to dipping, even in our curent enlightened era. It's also pretty clear that the composition or harshness of various dips has been less than standard through the ages of our modern hobby.
OK, now for the part I want to learn about......
For the sake of argument, let's assume we intend to dip a coin with a certain ubiquitous modern product that is sold in little cylindrical white and blue containers. In doing so, even a non-numismatist can see that a dark coin becomes brighter almost immediately. Which of the following statements is most true?
1) The dip solution removes silver-sulfur compounds, leaving whatever is left of the coin intact. If the corrosion was severe enough, surface irregularities responsible for luster were already lost and the coin now has a "lackluster" appearance. If the corrosion wasn't that deep, there is plenty of the original surface irregularity intact and that coin will retain whatever luster it still had, partially-hidden though it was by the toning.
2) The dip solution indescriminately removes a portion of the coin's surface. A quick dip will remove only the tarnish while an extensive dip will dig a little deeper, affecting the surface to the point that luster is lost.
I'm of the opinion that a dip will do nothing to change a coin's luster. Either luster was there before the coin was dipped (possibly hidden by the toning) or it had already been lost and the dip only revealed the already-damaged surface that was waiting to be discovered.
For the record, I think dipping is 95% bad, 5% good. Once a coin's original patina is gone, it's gone forever. A coin can never be "un-dipped". However, some coins can be rescued from PVC, previous poor attempts at "conservation", corrosion that is getting a little too far advanced, or toning that is just plain ugly to everyone who sees it.
What say you?
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I have dipped many silver and gold coins over my numismatic career and the results were always positive. These were both coins which needed a dip (usually pvc damage) and would benefit from it.
For newbies, its always a gamble. For experienced numismatists its all about knowledge.
Nobody can argue that dipping doesn't remove "something" from a coins surface but its the "whats underneath" that really counts as "original patina" can hide a multitude of unacceptable flaws, aberrations, and unsightly tiny hits. Spotting those before the dip is key to a successful "conservation".
The name is LEE!
as Lee stated, perhaps the most important thing is understanding which coins can gain from such a dip and which types of surface tone or "tarnish" can be removed easily and most effectively. also, proper rinsing is quite important and often over-looked. a good suggestion for an inexperienced collector would be to buy some junk silver and start with that to see what happens with the dip solution. further, a good approach is to use a diluted mixture of perhaps 50/50 which will slow the reaction and alleviate the problem of damage to some extent.
to the question "Which of the following statements is most true?" I would say statement #2 best describes what takes place with a solution such as E-Z-Est. sometimes luster can be hidden by tone and removing that tone will reveal the luster, but as the first reply stated the luster can and will be damaged by too long of a dip or repeated dipping. find some cheap junk silver with unattractive tone and try some dipping, it will be your best teacher. if you need help with a process send a PM.
This removes some of the metal from the surfaces.
It rounds the microscopic corners and edges on the struck surface, which affects the luster.
Dipping usually removes some oxidized metal, which reveals unoxidized metal, but with reduced luster.
Not to be confused with "decontamination" - immersion in a solvent, such as acetone.
This can remove contaminating deposited substances, without removing metal.
<< <i>I would say statement #2 best describes what takes place with a solution such as E-Z-Est. sometimes luster can be hidden by tone and removing that tone will reveal the luster, but as the first reply stated the luster can and will be damaged by too long of a dip or repeated dipping. >>
Keets, on this point I disagree. I've dipped enough melt-value stuff to have validated what makes sense to me from a chemistry point of view. Still, my experience messing with numismatic items of any significance is zero. I'll freely admit that I'm no chemist, but did have a decent exposure to the subject during my engineering and medical training. We also spent a decent amount of time on the effects of corrosion. I don't see how a long dip would have any greater effect to the coin than a short dip. Once the silver oxides and sulfides have been removed the metal that is left is pretty chemically inert. The concept of a flash dip for proof coins seems silly to me, from a theoretical point of view...... I guess I'll have to bust open some inexpensive silver proof sets and experiment a little...... Likewise, I can't see how dipping a coin 100 times in a month should be any worse than dipping it once.
I've never uncovered luster where I couldn't already tell it was there. Sometimes it takes a pretty bright halogen to see through the patina, but it's either there or it isn't. I also don't think I've ever destroyed any luster I was able to see. I've uncovered plenty of dull coins that were already dull and I've failed to perfectly restore lusterous coins which had areas where the toning was too severely imbeded into the coin's surface.
To me the real enemy is surface damage. Luster can't be recreated or restored once lost. Toning, by definition, is surface damage. A dip removes the damaged layer (which ironically acts as an inhibition to further corrosion to some extent) and exposes whatever is left. If the coin has enough flow lines remaining, it will still be lusterous, but never as good as it was when minted.
You and I are perfectly agreed on the importance of a proper rinse/neutrilization. Much of the crud I see on Peace Dollars is probably dip residue instead of planchet milk spots as is often claimed. I would also agree that understanding which coins would benefit is the real key. Being able to predict what sort of treasures and evils are lying under a layer of patina is certainly a specialist's art.
As far as the information on Tom Bush's site, I read through it again today and agree 100% with what is there.
A simple technique taught to me by John Albanese
Fill a bowl of some sort (cereal, soup, whatever) with about 1 1/2" of water. Place under a light. Put a toned coin in the water. Roll the bowl ever so slightly so that light reflects off the coin from different angles. Same as when rolling a coin in the light.
In cases where the toning is not too thick and the lustre strong, the light will strike marks and hairlines from a slightly different angle than when not under water. Some danger signals about what will be revealed after dipping will show up before that blue-white jar is opened.
Spend all the time explaining the science as you might like. Angles of refraction blah blah blah.
Practical advice. Totally non-invasive. Try it sometime. Might tell you yes, might tell you no, might tell you nothing. No downside whatsoever.
"I can't see how dipping a coin 100 times in a month should be any worse than dipping it once."
I highlighted these portions of your post because like you I'm not a chemist but from what I have read on the subject dip (as in ez-est) is an acid and it will eat away at the coin if the coin is exposed enough. It would seem if I understand your first statement that you feel once the tarnish is removed the acid will no longer react with the coin. It would seem that an experiment is in order, que the mythbusters. Take a junk toned morgan, weigh it, then do a quick dip, then weigh it again. Do this over and over increasing the amount of time the coin is in the dip. If you are correct and the dip is not reacting with the coin the weight will not be affected; or the coin will begin to shrink and the opposite is proven. Of course this would require a very sensitive scale for a proper test.
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Very interesting. I've noticed that toned coins look different when in an acetone bath too. Maybe it's the same idea. Maybe if I hold a lighted candle very close to the acetone I'll be able to see even better..........
Coinbuf,
An easier experiment would be to take a common-date, blast-white Morgan and leave it in the dip for a few days. It would be interesting to photograph it after a few minutes, after an hour, and after a few more hours. There are all sorts of things that could impact the results though. Coin planchets of that era are not known for being perfectly homogenous. Copper inclusions, impurities, lumps of carbon, and such could do some interesting things.
<< <i>An easier experiment would be to take a common-date, blast-white Morgan and leave it in the dip for a few days. It would be interesting to photograph it after a few minutes, after an hour, and after a few more hours. >>
My copy of "The Coin Collector's Survival Manual" shows pictutes of a coin before dipping and after a 15 second dip. There are differences in the pictures. On the other hand, how many coins get dipped (even over time) that long?
Do not mix acetone and dip. the results are unpredictable
Do not sniff acetone and dip. The results are predictable.
Perhaps this warning came a little late
<< <i>Spend all the time explaining the science as you might like. Angles of refraction blah blah blah.
Practical advice. Totally non-invasive. Try it sometime. Might tell you yes, might tell you no, might tell you nothing. No downside whatsoever. >>
- Col. Jessup
Hi Col, J.
Agree. Great suggestion! I think this is an example of changing the refractive index. A practical example we all can see is when you wet a scrap of black construction paper. It appears darker. Just like bringing out the saturation of an oil painting with varnish.
Best wishes,
Eric
I totally agree with keets regarding cleaning after a dip, it is critical.
Cheers, RickO
<< <i>
<< <i>An easier experiment would be to take a common-date, blast-white Morgan and leave it in the dip for a few days. It would be interesting to photograph it after a few minutes, after an hour, and after a few more hours. >>
My copy of "The Coin Collector's Survival Manual" shows pictutes of a coin before dipping and after a 15 second dip. There are differences in the pictures. On the other hand, how many coins get dipped (even over time) that long? >>
Those pictures are junk science. The luster peaks didn't get eaten away. The luster valleys got filled up with a well known by product of thiorea that seems to be dependent on minerals
such as iron and chlorine in tap water used for rinse. Conservationists since the early 1980s have used rinsing in 200F deionized water to minimize this effect on silver. The coin people apparently didn't get the message.
<< <i>
<< <i>I would say statement #2 best describes what takes place with a solution such as E-Z-Est. sometimes luster can be hidden by tone and removing that tone will reveal the luster, but as the first reply stated the luster can and will be damaged by too long of a dip or repeated dipping. >>
Keets, on this point I disagree. I've dipped enough melt-value stuff to have validated what makes sense to me from a chemistry point of view. Still, my experience messing with numismatic items of any significance is zero. I'll freely admit that I'm no chemist, but did have a decent exposure to the subject during my engineering and medical training. We also spent a decent amount of time on the effects of corrosion. I don't see how a long dip would have any greater effect to the coin than a short dip. Once the silver oxides and sulfides have been removed the metal that is left is pretty chemically inert. The concept of a flash dip for proof coins seems silly to me, from a theoretical point of view...... I guess I'll have to bust open some inexpensive silver proof sets and experiment a little...... Likewise, I can't see how dipping a coin 100 times in a month should be any worse than dipping it once.
I've never uncovered luster where I couldn't already tell it was there. Sometimes it takes a pretty bright halogen to see through the patina, but it's either there or it isn't. I also don't think I've ever destroyed any luster I was able to see. I've uncovered plenty of dull coins that were already dull and I've failed to perfectly restore lusterous coins which had areas where the toning was too severely imbeded into the coin's surface.
To me the real enemy is surface damage. Luster can't be recreated or restored once lost. Toning, by definition, is surface damage. A dip removes the damaged layer (which ironically acts as an inhibition to further corrosion to some extent) and exposes whatever is left. If the coin has enough flow lines remaining, it will still be lusterous, but never as good as it was when minted.
You and I are perfectly agreed on the importance of a proper rinse/neutrilization. Much of the crud I see on Peace Dollars is probably dip residue instead of planchet milk spots as is often claimed. I would also agree that understanding which coins would benefit is the real key. Being able to predict what sort of treasures and evils are lying under a layer of patina is certainly a specialist's art.
As far as the information on Tom Bush's site, I read through it again today and agree 100% with what is there. >>
You're certainly welcome to your opinion but the fact of the matter is that dipping will indeed destroy the luster of the coin given enough exposure to the dip.
I know this to be a fact since I've proved it to myself.
I conducted a dip test on a 40% Silver Clad Eisenhower dollar many years ago and reported the results which even after many hours in E-Z-Est were negligable.
I've done the same test with a 40% Silver Business Strike with negligable results.
However, an experiment on a lustrous Morgan ended with disaster by ruining a perfectly good MS63 coin. These being 90% Silver do not tolerate dip as much or as readily as 40% coins. Silver Eagles at 99.999 fine are even less tolerant.
Know this: Regardless of the results you've seen first hand, which were more than likely preselected coins with minimal dip exposure, dipping will destroy a coins luster and in so doing, destroy any numismatic value the piece may have had.
I know this from first hand experience.
Something else I know. A dipped silver coin will not re-tone for a very, very long time as the dip removes certain contaminents which are required for the natural toning process. Such things inlude oils which are imparted during the minting and bagging processes. Once these are gone, the coins normal notural toning capabilites become greatly reduced.
This is possibly the reason that Peace Dollars tone differently than Morgan Dollars as there were different manufacturing rinses available in the late 19th Centruy than the 20 Century.
The name is LEE!
<< <i>An easier experiment would be to take a common-date, blast-white Morgan and leave it in the dip for a few days. >>
I encourage you to do just this!
Besure to photograph every step.
Might I suggest haveing two similar coins. One which acts as the control coin which never gets dipped and one to rui.....I mean dip.
Photographing both coins, side by side, after each step would enable us, the viewers, to draw our own conclusions.
The name is LEE!
Acid will eat silver. The strength of the acid determines how fast it will eat it. Drop it in some battery acid and watch it go away.
Dilute acid dips for a few seconds slows the reaction, but the reaction is there. The Swiatek sponsored research in the Travers book, is sound, although I wasn't there so I don't know if it was conducted properly.
If you are good enough to dip something and rinse it fast enough that you only get one layer of atoms...you must be very, very good. I think Swiatek stated that one dip won't hurt...it's the 9th or 10th one that hurts and are you good enough to know which one this is?
<< <i>I was a chemist in a prior lifetime, meaning I had 32 credit hours of Chemistry in college and worked as a chemist and chemical engineer. That was a loooonnnnngggg time ago.
Acid will eat silver. The strength of the acid determines how fast it will eat it. Drop it in some battery acid and watch it go away.
>>
E-Z-Est is 2% sulfuric acid by weight. pH of 1.5 makes it a bit more acid than a Coca-Cola, not as acid as vomit. But sulfuric acid is not reactive to silver
in ANY CONCENTRATION. The acid is there because thiourea, the active ingredient, requires an acid environment to convert tarnish (silver sulfide) back into
metallic silver (which is redepositied on the coin) and hydrogen sulfide gas (rotten egg smell when you dip a coin)
And it's multiple "tarnish-dip-break bonds-redeposit silver" cycles ---along with contamination byproducts due to improper rinsing -- that produce the
"overdipped" coin.
(Guess I need to save this as a text file...the same old misinformation will be posted again in a few months)
What you're saying sounds about right to me. The acidic environment to promote the reaction of the thiourea sounds right. It's been way too long for me to remember how to look up the reaction potentials of silver salts. I'm not so sure about the redeposition idea, but obvioulsy the silver has to go somewhere. I would assume it remains compounded with the thiourea in solution, but....... not sure.
Typical US silver is only 90%, so the other stuff (mostly copper) probably plays a role here too.
I think I'll try some "home chemistry" soon. I have a couple of nearly identical, frosted, white, lusterous peace dollars worth only melt due to some surface injuries. I'll pick up some EZ-est next time I'm near a coin shop. For the purposes of the experiment, I'd recommend comparison photos after 5 seconds, 10 seconds, 30 seconds, 2 minutes, 10 minutes, 30 minutes, 2 hours, and 12 hours. My own theory is that there will be no visible luster impairment prior to 30 minutes, which would represent a hundred eternities in the world of numismatics. I will be very happy to be proven either right or wrong. Anyone want to suggest a different experiement design? I might also try to find a heavily toned, but lusterous dollar to play with too. I just might have a candidate 1924 coin in mind. Keeping the photography uniform will be a simple matter.
19Lyds idea of impurities on the coin being necessary to natural toning is interesting. Obviously there are real reasons that some series tone nicely and others don't. I'm willing to entertain the idea that oils, storage conditions, or differences in the planchet preparation plays an important role. Work hardening of the various bits and pieces of the surface design is probably also chemically important and is very design-dependent.
I seriously doubt that this discussion will ever satisfy anyone other than to accomplish boundaries
-Some collectors find enhancing coins offensive
-Others really seem to be oblivious to the consequences
There are enough dipped coins to go around- that is not the case for original coins.
As collectors and people who should know better, govern yourselves accordingly as future generations are going to look back at this time with distain...
We knew better and nothing compelling was done to institute a fundamental change in connection with the thinking of originality and preservation. These concepts as to coins seem to be misunderstood more than the question posed in this thread.
Greed is not always good.
Experience the World through Numismatics...it's more than you can imagine.
Well said. Every time another messed-with coin bites the dust it makes the ones that are left that much more rare and that much more valuable.
Still, there is an important distinction to make. Is it the act of dipping that damages the coin or is it the formation of tarnish? I'll propose that the actual destructive act is the formation of tarnish itself. This represents a chemical change to the coin's surface. A subsequent dip just strips away what was already lost, revealing either residual luster or a dead coin depending on how much damage had already been done.
Maybe the truth is in in the middle. It will be interesting to see just how hard it is to ruin the luster of a white coin by dipping alone.
Last year at Summer Camp I had one of the best-of-all-time practical jokes played on me.
In trying to demonstrate the effects of over-dipping, I left a silver 25c in a bowl of full-strength Jewel-Luster on the table overnight.
I got to class a little late the next morning.
Bill Fivaz was sitting in as a Roving Instructor. He's got this big grin on his face. I went over to the bowl and looked in. My eyes popped.
Bill
After
What are we looking at here? Before & after of a quick dip, an overnight bath in the dip vat, 100 dippings, what???
EDIT: It was dipped 18 days ago and so far the coin is white and very natural looking IMO. I think it came out just fine, heck of a lot better than the before pic.
"I might also try to find a heavily toned, but lusterous dollar to play with too. I just might have a candidate 1924 coin in mind."
As collectors and people who should know better, govern yourselves accordingly as future generations are going to look back at this time with distain.
We knew better and nothing compelling was done to institute a fundamental change in connection with the thinking of originality and preservation.
These concepts as to coins seem to be misunderstood more than the question posed in this thread.
Greed is not always good.
Bravo!!!
then why ask the question if you have already formed an incorrect opinion which most others have pointed out??
Also, what's the point of soapy water after the dip. Before the dip is when you want to dislodge surface crud. I've used acetone so often I never have to do the dishes. Goo-Gone occasionally, even on gem proof type with no adverse effects.
Soaking/rinsing multiple times in fresh acetone can never be bad. Replace your Jewel-Luster often too. Never re-use J-L with different metals. Nickel before silver really stacks the odds against you.
The point has been made before, it's being discriminating that's most important. Hairlines can hide under PVC. Or what some generically reference as "putty"
Anyone else using an ultrasonic?.
I'm not (that much of) a show-off, but I've been given 5 figure coins to "conserve" by other dealers and a few collector friends. I've hurt very very few.
An ounce of prevention is worth a pound of cure
Edited to add: dilute your dip dammit. Everything that can be done fast can be done more safely slowly. You can always pump up the dosage later. Anyone ever put too much pepper in the chili?
I would propose that the act of asking for input about an opinon, or more correctly, a hypothesis, might be useful to the one posing the question. Such is the very point of having the discussion in the first place. I'm willing to accept that the hypothesis is flawed - proving that would be very usefeul! Unfortunately, thus far there has been an abundance of hearsay and opinion and a complete lack of evidence on the subject.
Much finger-pointing and blame has been directed to the damage a dip can cause to the surface. Perhaps leaving a lusterous quarter in a solution overnight can cause profound damage - maybe even enough to change it to a dime.
It might also be fun to compare two lusterous coins.....
A is quickly dipped fifteen or twenty time for a few seconds each time. Serial photos are done after each bath.
B is lightly artificially toned and then subjected to the same dip. After each bath it is toned again.
There is no guarantee that the process of artificial toning would chemically replicate what happens when coins tone naturally, but I'm not prepared to devote my life or lives of my grandchildren to the pursuit of an answer.
After 10 or 15 cycles will there be a visible difference? Will the untoned but repeatedly dipped coin fare better?
It would be very fun to have access to a scanning electron microscope so that the effect on the surface irregularities could be quantitatively evaluated. I seem to be fresh out at the moment.
<< <i> It would be very fun to have access to a scanning electron microscope so that the effect on the surface irregularities could be quantitatively evaluated. I seem to be fresh out at the moment. >>
ANACS, when it was still part of ANA, was publishing SEM images of this, or at least gross results of surface metal flow degradation, 40 years ago. .
a few thoughts................
--there has been quite a bit of first-hand experience offered that dipping can damage the surface/luster of a silver coin, the OP simply chooses to reject it. those of us who have had bad experiences with dipping or who have already performed the "experiments" you propose are not making things up.
--deep toning doesn't necessarily take a very long time. the storage conditions are the actual determinant as evidenced by some of the ASE's, just PM coinsarefun. Proof coins tend to tone deeper at a faster rate, hence, my suggestion that you over-dip a Gem Proof coin
--it is almost guaranteed that when this topic is started and runs a page or two the inevitable "scanning electron microscope" suggestion is made.
Over-dip is why it's High School Chemistry to dilute your dip.
I look at every new coin as a virgin. Me, not them. Just to get the visceral experience, Then my pattern-recognition wet-ware kicks in. Then, I consider a lot of things. One of more than a few of them is whether dipping could possibly be helpful? Working definition of "helpful". Can I make money? Is the toning deep or, rather, rich? What's the likelihood of a dip working? What's hiding that's an impairment? An unrevealed virtue? How much will I lose if it doesn't work? How much will I make if it does?.
Dave Akers knew I dipped coins. Called it "coin murder" but much more so about others who did it more indiscriminately. The right two coins out of ten working can pay for a lot of failures. Not that I ever had ten hard-mirror blah-toned Barber 25c proof at one time, but a few hits going from 64 to 66, 65-67DCAM, once OGH 65 to 68CAM, they keep you in the game.. Easy to guess the CAM/DCAM dates if you follow the proofs. Best Dave could do was nod and moderate his frown when I told him I killed a lot fewer than others. There were plenty of other more pleasant things to talk about.
Moralize or psychoanalyze all you like. Dipping is not a primary-presenting diagnostic of antisocial personality disorder. For many, it doesn't even feel naughty.
Grading is about the quantification of virtue. I overheard a dealer say he didn't mind paying more for some CAC proofs because so many "B+" coins dipped out well. The underlying reason was the underlying surfaces.
Don't blame the player. Blame the game. Markets are amoral.
Show me an 1896 any denomination PR66, beaned or otherwise. Want to sell it?
From "Dogs" by Mary Oliver "Here is hope retching, the world as it is".
Back to capitalism
Big meeting, must have been Long Beach, then the greatest of all the national shows. Presentation by David Hall about letting a few more barbarians through the gates. Some of what we heard was about trading qualifications ,submitting mechanics and scheduling, and especially the grading process. Most of the probably over 100 dealers knew amongst them who made their word good and who had knowledge set, and access to buyers and sellers, and technical skills,
Mark Feld has mentioned Magic Mark. At the meeting David offered a $10,000 bounty on coin doctors. PCGS was, and is, working to create value by giving a moral market quantification and nuanced values to coin evaluation, and thus to valuation.
At the end of the meeting, Magic Mark walks up to David Hall, wrists upturned, extended, waiting for the cuffs, and said "I'm turning myself in for the reward". Much a joke but the financial implications on niches where and when doctoring had impact were little.. Grading has been refined, a direct result of its taxonomy extending and deepening. Better mousetraps are needed for smarter mices.
And on the other hand I know some originality, virginity is lost and some treasure it. Archival conservation imparts historicity, and has much virtue. I wouldn't think of arguing against that. And many will survive.
It's a market. chacun a son gout. Sympathy, but, amorally,
Market arguments and personal taste each have their theologies. I've got no answer.
The EAC guys know a unsuccessful chemical intervention, and besides some emulsifiers there are very very few, represents and is valued less because it contravenes their mission statement and evaluatiion paradigms.
The cognoscenti like a good camel's hair brushes.
<< <i>hey Col Klink, too many big, foreign words in there for me, but I liked the post!!
Preservation Dipping Doctoring Markets Risk/Reward.
<< <i>a few thoughts................
--there has been quite a bit of first-hand experience offered that dipping can damage the surface/luster of a silver coin, the OP simply chooses to reject it. those of us who have had bad experiences with dipping or who have already performed the "experiments" you propose are not making things up. >>
Keets, I think we're just coming at this from different directions. You misinterpret my comments. I have heard it said that dipping does nothing but remove toning. The idea that corrosion itself and not the removal of it is what causes damage is an intriguing hypothesis, but show me EVIDENCE to the contrary and I'm perfectly willing to accept the hypothesis as false. If you'll look at the thread title I chose the word "science" for a reason. The "first-hand experience" that you refer to is just talk. Almost 100% of what has been offered in this thread is anecdotal evidence. For most people that's probably good enough. You and others of your opinion may actually be correct. But, by the time such makes its way to an Internet forum (a marvelously imperfect way to exchange ideas), the information is second-hand at best. I will be very happy to accept evidence. I can't get anyone to provide any (see any photos in this thread?), so I'll have to discover it for myself I guess. I wouldn't expect everyone to see the utility in exploring the topic from a scientific perspective. That's OK. If the discussion annoys you or has been re-hashed too many times for your appetite that's fine - just ignore it.
<< <i>--deep toning doesn't necessarily take a very long time. the storage conditions are the actual determinant as evidenced by some of the ASE's, just PM coinsarefun. >>
ASE's are a different alloy (almost pure silver) and are therefore chemicially much, much more reactive. The chemistry between them and 90% silver is probably too different to draw many conclusions.
<< <i>Proof coins tend to tone deeper at a faster rate, hence, my suggestion that you over-dip a Gem Proof coin >>
A layer of toning might be more visually apparent on a mirrored finish, but that doesn't necessarily mean it's deeper.
<< <i>--it is almost guaranteed that when this topic is started and runs a page or two the inevitable "scanning electron microscope" suggestion is made. >>
Yep. It's a useful scientific tool. If you simply enjoy the hobby without needing to know the details of what such an evaluation might yield, that's fine. Just taking a peek at the coin before and after is probably good enough for most people.
more to the point, "just taking a peek at the coin after" works for most professional and ordinary Numismatists because the affect of a dip most readily announces itself as muted/damaged luster. that makes sense since luster is very thin, delicate and on the top surface of a coin. knowing what was there before isn't necessary because only two things will remove luster-----friction and a chemical reaction. lack of luster from the former can be seen, lack of luster from the latter can also be seen as a muted dull area. also, my suggestion of using the ASE's and Proofs is sort of the opposite of my suggestion to use a diluted mixture when dipping, the purity and delicate surfaces will show a result much quicker with the coins not needing to be toned.
this is a topic which can be debated ad nauseum. I have tried to share my experience, as others have yet your choice is to debate rather than to trust those experiences. please continue in my absence and have a nice day.
<< <i>
this is a topic which can be debated ad nauseum. I have tried to share my experience, as others have yet your choice is to debate rather than to trust those experiences. please continue in my absence and have a nice day. >>
You have your experience, which is appreciated, but your experience is by no means universal, and in fact does not match mine. My thoughts are very much in line with BryceM. This is why the debate goes on.