At work so this will be quick. I did NOT say I dipped these coins for 15 seconds. I said that if you dip a coin any longer than 15 seconds would be a bad thing to do. Be back on this evening.
OK, but your previous message implied that you did. And I said if you dipped it for longer than 1 or 2 seconds it would be harmful. Even 3 seconds is too long. That is my only point.
Proper dipping involves a 1-2 second dip followed by a THOROUGH rinse with distilled water. Some coins are good candidates most are not! My two cents. 15 seconds and you have some washed out lusterless bullion at best.
Left to right, top to bottom, 1,3,9,11,13. Those are the dipped ones. And they were dipped for about 3 seconds. And I implied nothing. I stated flat out if it is done wrong you can damage the coin. As for those in the pic. The first one was tarnished very badly. So picking that one was truly easy. The other two, props to you. Tell me this. A couple microns were taken off by dipping. What is it that you look for that will tell you that a coin had that minute a change?
It's not something that I can easily explain other than to say it takes experience. A coin that has been truly over-dipped almost anyone can identify. A coin that has been dipped a bit too long just has a "look" to it. The luster changes. When I can sit down side by side with a person and look at coins in hand, tilt and turn them in the light, then I can explain it because then I can show them and compare the subtle differences. But when using pictures it's all but impossible. I will say this, had you dipped those coins for only 1 second, maybe even 2, I doubt that I could identify any of them even in hand. But the fact that I could easily pick out 3 out of 5 from a group picture and be right should illustrate that what I am saying about dipping and the time factor is correct. As for the other two that I picked, they may well have been, and probably were, dipped before you ever got them.
Indeed...pictures are nothing but a approximation of a coin. You cannot make an informed decision based on pictures. It seems in these days of the internet some people seem to think that pictures are the end all.....far from the truth. You haven't truely seen ANY coin until you hold it in your hand, use your eyes and tilt/rotate it. A picture only shows a fraction of the story and they are easily manipulated to cast an impression that may not necessarily be accurate.
I agree that cleaning will ruin a coin in the ms-65 + class. But I honestly see no harm in cleaning a circulated coin. There is no cartwheel effect and slight wear is easily detectable. I always assume that any coin minted before say 1970 has been cleaned, unless it is in a mint set. Now I am also not talking about whizzing, or acid baths burt simple getting the crud off. So long as no fraud is involved or attempted. However, I know this subject has been beaten to death for many years. Anyway, good to hear what folks have to say.
Doug, yes I agree that anythign longer than a second or two, and not rinsed immediately with pure water, will take the "edge" off a coin. That is the best I can describe what you refer too, the tiny microns on the surface have the highest luster, so dipping takes off the "pop" slightly of a fresh BU coin. Everyone remember that the cartwheel effect is caused by the melting on the surface during the strike, and is strongest at the surface, decreasing every atom down from there. I guess I didn't read on his post how long it was. I have never dipped a coin longer than a second unless it was already near basket case territory, (black toning).
OK, my last entry on this thread. First, I am well aware pics are not the end all. I do believe I said pics were not the best thing for this. Second. No, none of those were already dipped. They are all uncirculated. *GASP* He dipped unirculated coins!!!! Yep, guess that confirms my status as a fake collector. Anyway, to see if " 15 seconds and you have some washed out lusterless bullion at best" is true, I dipped the following quarter for 16 seconds. It is a circulated proof that I found in a drawer at work. So, as it was already scratched to hell, I sacrificed it to the coin Gods for this. On the left is before, right is after. While pics are not the end all, if it was reduced to the equivalent of lusterless bullion, I do believe a blind man could indeed see that. And I understand it isnt silver, and silver acts differently, so no need to point that out to me. But a proof coin, even circulated, should show some serious damage if all that you folks have said was true.
smoke - the vast majority of coins that have ever been dipped are Unc coins. And there's nothing worng with dipping a coin when it is done properly. Every collector there is owns many, many coins that have been dipped. They may not realize they own dipped coins, but they do. Experts estimate that 80% or more of all older coins have been dipped. The only reason I made any comments at all in this thread was to make sure that those who have no experience with dipping coins realized that the length of time involved in dipping is so critical.
For pennies I use apple cider vinegar. I had a 1984 with a large blob on it, and I was curious last night, so I put it in the vinegar and went to bed. This morning, I used Polmolive soap and a horse hair brush to remove any vestiges of corrosion. Then I sprayed it with high pressure tap water, and finished with distilled water as a rinse. In theory this will stop the process of the corrosion which the cider vinegar began. Whatever you put on the coin is acidic. It makes the coin shed it's skin, if you will. I will post the results after UNC finishes today.
Dipping tip-off. So the sure fire way to tell if a coin has been dipped is simply luster? If that is the case, I think I'll buy some coin dip and try and see if that is true to the eye. I have never used a coin dip, and it's horrifying to find long-time collectors who do it routinely. Seems deceptive.
I have been told to use denatured alcohol to remove grease from coins, dip for 30 seconds then gently blot or rub with 100% cotton. I tested it on a junk dime, and so far I haven't noticed anything. What do you all think?
Nothing wrong with the alcohol. But rubbing with anything is a very bad idea. I don't even like to tell people to blot or pat the coins.