Hello and welcome to my 25,000th post celebration! Today I want to share my latest and probably another controversial NGC Attributed Mint Error.. It is 1984 Copper Plated Zinc Cent Obverse Lamination I have been in communication with CT member @Pete Apple concerning this coin. The issue is that it is possible to have a Lamination issue on Copper Cents. They are well known. But when it comes to plated Cents. Is it really a Lamination? Pete even wrote an article in the latest issue of CONECA about this matter before even knowing that I own probably the only known specimen of such a coin. (So I think ) Here is Pete Apple's thread - https://www.cointalk.com/threads/check-out-my-paper-in-errorscope.345874/#post-3682161 I invite Pete, my good mint error specialists friends to comment to give their thoughts! Especially @Fred Weinberg
Very cool Paddy. Congratulations. 25,000 people you've helped or pissed off lol! I personally appreciate the fact that you comment here as Im sure others do too. Without members like yourself taking the time to hit us with TRUTH, I honestly wouldnt be into this hobby at all. It would be impossible to do this without an experienced human eye. Going just by what can be read and pictures to look at, I dont think it can be done efficiently....or done having fun! Thanks for contributing to this hobby! Its very clear that without people like yourself, people would be saving alot of coins that are simply MD or PMD thinking they were worth hundreds.
I was wondering about that same point if the copper plated zinc cents are really laminations or some long plating blister. I mean I guess the plating could flake or peel, but it's so thin. They graded/ attributed it. But there's no explanation. Perhaps Fred can enlighten us when he sees this thread.
Interesting. Everything I've read says that copper plated cents cannot have laminations. Looking at the coin in question, it looks to me that it was part of a linear plating blister running across Abe's face that popped or was ruptured somehow. Again, I'm no expert and we all know that TPGs are infallible and never ever ever make mistakes so I must be wrong
Interesting indeed. I would not call it a Lamination In the true traditional Numismatic definition of Lamination. A more modern definition needs to be established to describe this type of anomaly. Something that properly describes this new type of error created from a relatively new coin manufacturing process. Something like "Electro-Plate Flaking" or "Veneer Flaking". It is a bit disheartening that it resides in an improperly labeled slab. And beyond that I personally would not call this coin a Mint Error due to the fact that cent planchets are outsourced to a private manufacturer and not made at the mint. And that is my opinion and others will form there own with or without proper information. http://www.error-ref.com/lamination-loss-after-strike/ https://www.comsol.com/blogs/electroplating-u-s-mint-makes-penny/
I do think that the word on the slab: "Lamination" is not used in the same way as is common in numismatics. As I look at the coin it certainly appears to be a plating disturbance. I agree that the slab reflects an incorrect attribution. I would also note that the second link mentioned gives the thickness of copper plating at 20 microns. It is in fact 8 microns. I have received permission from CONECA to share my paper "WHY ARE COPPER PLATED ZINC CENTS RESISTANT TO LAMINATION? here.
Thanks for the correction. He calls them Pennies also. I think he means well though. Enjoyed reading your article. Very interesting result on the negative strain hardening rate. Thank you for posting it.
Thank you. I double checked my source for Zinc Cent Copper plating @ 8 microns thickness. It is: ALTERNATIVE METALS STUDY Contract Number: TM-HQ-11-C-0049 FINAL REPORT August 31, 2012 Submitted to: United States Mint 801 Ninth Street, NW Washington, DC 20220
I read a bit further in the article here: https://www.comsol.com/blogs/electroplating-u-s-mint-makes-penny/ The article implies that a cent is plated after passing through the coining press which stamps the cent, thus placing the devices on the cent. It is not. The planchets are plated via a barrel plating process at Jarden Zinc, the supplier of the planchets to the US Mint.
Well, it is possible for lamination of individual clad layers on clad coinage. Kind of tricky with zinc cents though. I guess we would have to know if the lamination of the copper plating on a cent has separated from the copper itself rather than merely separating from the zinc. If the lamination of copper comes off leaving copper underneath the separated area, that would be a lamination. It there is zinc showing under the flaked area, I would refer to it as a defective planchet. I wonder if there has ever been a lamination of the zinc on a 100% unplated cent?
Thank you for this information and the work you put into it to give others a better understanding of the science. I find it quite interesting that the zinc coins do not acquire work hardening during the striking. The Rockwell test show a negative strain hardening. To me that indicates a zinc planchet actually gets softer when struck into a coin. This must be a factor in why the 99.08% pure zinc is so reactive when exposed to the environment. But then zinc is used in the galvanization process as a corrosion resistant coating on steel implements and structures.
I was searching for the weight of an un plated zinc cent and found this thread. I was wondering if it was called a lamination because there is copper underneath the area that is peeling, and not zinc. If there was an overlap of copper, I could see the Lamination error. It's doubtful in my mind that this could happen, But my two cents.
