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 Replies: 26 / Views: 2,437 |
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Pillar of the Community
 United States
3330 Posts |
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It is the edge itself, and not the surface near the rim, that has double plating. This sounds problematical to me. I cannot imagine how it would be accomplished in a barrel plating process where the planchets are tumbled in a barrel with electrolyte! I hope you can find the reference! Thanks for the input/dialogue! |
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Bedrock of the Community
United States
19158 Posts |
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Pillar of the Community
United States
3330 Posts |
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Excellent material! Researching plating has been fun, and also:  Fascinating Frustrating Challenging I keep finding more alleys to explore and more lines of research to check! So far, I have 2 more papers to share = one on Plating Cracks and Splits and one on Proof Cent Plating. The Mint has been of some help but is withholding information on some questions. I am considering a FOIA request, but suspect a response under Exemption 4, which protects action obtained from a person that is privileged or confidential trade secrets and commercial or financial information. Edited by Pete2226
04/08/2025 10:33 am
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Pillar of the Community
 United States
5774 Posts |
Thanks so much for addressing my questions and providing so much information.
Another question that comes to mind.
Is there any way to determine it these "ridges and valleys" become more pronounced after a coin is released into circulation?
Are the tops of the ridges flattened by the strike?
Are there any changes happening in the atomic level from the substrate oxidizing?
Thanks again for your insight.
Words of encouragement are one of the major food groups.
We need to consume them regularly to thrive and grow.
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Pillar of the Community
United States
3330 Posts |
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1. Is there any way to determine it these "ridges and valleys" become more pronounced after a coin is released into circulation?
2. Are the tops of the ridges flattened by the strike?
3. Are there any changes happening in the atomic level from the substrate oxidizing? 1. Unable to answer this - I cannot think of a way to gather the data required for a proper answer! 2. One of my unanswered questions is the effect of the strike on a planchet with corrugation. To me, it is counterintuitive that a strike would not completely obliterate any existing ridges and valleys. However, you make me think of one experiment that Ken Potter and I worked on jointly: We were working on Rockwell Test Marks. See my paper from some years ago here: https://conecaonline.org/rockwell-h...ncoln-cents/I had a Rockwell Test performed on a cent. That it was done after the strike is evident from the pressure ridge around the mark - a strike will obliterate it. It turns out that a strike does more - it deforms the mark extensively! Ken took that coin some years later and had it struck into his 50th Anniversary of Serving Collectors Medal. The following photo shows the effects of that strike. Notice that the surface of the field of the coin is NOT totally flattened, which I would have expected it to be! This tells me that the Ridges and Valleys are quite capable of surviving the strike!  3. I have seen no studies that mention the oxidation of the substrate beneath the plating. Edited by Pete2226
04/10/2025 10:29 am
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Pillar of the Community
United States
5774 Posts |
I'm not sure if this image of a recent purchase is helpful but it is a 2005 D with a planchet error that appears to have happened before the plating process (at least before the process was completed). This coin shows the "corrugation" on the normal fields of the coin as well as a few inside the missing area, although not as plentiful.     Words of encouragement are one of the major food groups.
We need to consume them regularly to thrive and grow.
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Pillar of the Community
United States
3330 Posts |
Quote:
I'm not sure if this image of a recent purchase is helpful but it is a 2005 D with a planchet error that appears to have happened before the plating process (at least before the process was completed).
This coin shows the "corrugation" on the normal fields of the coin as well as a few inside the missing area, although not as plentiful. Fascinating! Thank you! I hope it will be okay if I use your photos, should the opportunity arrive! Looks to be a fine example of plating cracking and peeling! Some TPGs might call this a lamination because they usually do not use the numismatic definition of lamination which is separation of an alloy along horizontal planes of weakness. I think they are in error! |
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Bedrock of the Community
United States
19158 Posts |
Interesting planchet issue, yes!
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Moderator
United States
188560 Posts |
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This coin shows the "corrugation" on the normal fields of the coin as well as a few inside the missing area, although not as plentiful. Nice example!  |
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Pillar of the Community
United States
5774 Posts |
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Fascinating! Thank you! I hope it will be okay if I use your photos,... Yes, of course you are welcome to use them anytime. I'm glad to help the hobby. If it's ok, I'd like to send you a link to an album I created for all the images of this coin. You are welcome to view them, use them, or toss them. Let me know if it's ok. Thanks. Words of encouragement are one of the major food groups.
We need to consume them regularly to thrive and grow.
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Pillar of the Community
United States
3330 Posts |
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Yes, of course you are welcome to use them anytime. I'm glad to help the hobby.
If it's ok, I'd like to send you a link to an album I created for all the images of this coin. You are welcome to view them, use them, or toss them. Let me know if it's ok.
Thanks. Yes! Please do! Thank you! |
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Replies: 26 / Views: 2,437 |
First Page
Posted 04/08/2025 10:08 am
