| Author |
 Topic  |
|
|
n/a
deleted
15 Posts |
 Posted - 04/17/2007 : 21:04:58
|
Hello all-
While searching for pre-82s, I came across an oddity: a 1986-D cent that has no trace of the copper plating, and instead has the same color as a 1943 steel penny (although a magnet doesn't stick, of course). Has anyone seen one of those? It's in good shape.
|
|
|
psi
Penny Collector Member
Canada
399 Posts |
Posted - 04/17/2007 : 22:29:04
|
| I wonder how someone would go about removing the copper plating without destroying the zinc inside. It seems like it's a lot easier to dissolve zinc in acids than copper for example. Maybe something like electroplating in reverse? |
 |
|
|
n/a
deleted
59 Posts |
Posted - 04/17/2007 : 23:58:26
|
I don't know how you'd get the copper off and leave the zinc intact. My guess is that it never got coppered in the first place.
-------------------------------------------------------------------------------------------------------------------
One of the chief attractions of the life of the wilderness is its rugged and stalwart democracy;
there every man stands for what he actually is, and can show himself to be.
-- Theodore Roosevelt |
|
|
|
horgad
1000+ Penny Miser Member
USA
1641 Posts |
Posted - 04/18/2007 : 07:40:26
|
Ive found two silver colored pennies (after searching 20k pennies) that were plated after they were minted. I about flipped the first time I found one. One is from a year when somebody was making penny bracelets. I found a listing on E-Bay for a bracelet that had pennies matching the one that I found. The other was just plated as some kind of promotion...seems like there is a few hoaky coin places (Franklin Mint?) that plate coins, up the price, and sell them as something special.
If you really think it is not replated (on top of the copper plating), I would guess somebody put it in acid for fun... I have not heard of any coin errors where the mint is making pure zinc pennies...
In the 20k or so pennies that I have looked through, besides the 2 worthless silver plated pennies, I also found my first error penny (an 82 copper cull). It might be worth a buck. Maybe someday I will get a picture of it up... |
|
|
|
n/a
deleted
59 Posts |
Posted - 04/18/2007 : 13:26:35
|
I'm not a chemist, but I think any acid that would dissolve the copper would dissolve the zinc as well. You can do the opposite though: make a cut through the copper layer, put it in acid, and dissolve the zinc center, leaving just the copper shell.
You must be logged in to see this link.
You must be logged in to see this link.
-------------------------------------------------------------------------------------------------------------------
One of the chief attractions of the life of the wilderness is its rugged and stalwart democracy;
there every man stands for what he actually is, and can show himself to be.
-- Theodore Roosevelt |
|
|
|
horgad
1000+ Penny Miser Member
USA
1641 Posts |
Posted - 04/18/2007 : 13:34:02
|
"I think any acid that would dissolve the copper would dissolve the zinc".
Agreed, I was thinking they dipped it in acid long enough to remove the copper but not long enough to disolve the whole thing. If that was the case, I would expect at least some pock marks on the zinc. |
Edited by - horgad on 04/18/2007 14:05:47 |
|
|
|
Gresham
Penny Pincher Member
184 Posts |
Posted - 04/19/2007 : 00:23:06
|
| It works though. If you are quick enough you can remove the penny before the zinc dissolves. I have one that was made just that way on a shelf at home. |
|
|
|
Gresham
Penny Pincher Member
184 Posts |
Posted - 04/19/2007 : 00:43:48
|
As to the pock marks. You must be expecting that a drop of acid slowly eats through the surface. If it is "soaked" in concentrated nitric acid then the surface is evenly exposed and the coin just becomes a little smoother. Of course if some acid is left on the bare zinc surface then it will develop pock marks.
I can still see alot of the details of the coin. I'd grade it as a very good. |
Edited by - Gresham on 04/19/2007 00:50:20 |
|
|
|
Metalophile
Penny Collector Member
USA
320 Posts |
Posted - 04/19/2007 : 01:09:17
|
As a teenager I plated a few cents with silver. I used silver nitrate solution. I believe I posted about that a few months back.
Metalophile |
|
|
|
HoardCopperByTheTon
Administrator
USA
6807 Posts |
Posted - 04/19/2007 : 01:09:53
|
I have found a few of those as well. My theory on how it is done is through electrolysis. Sort of the opposite of the way coins are plated in silver and gold as novelty items. There is a cathode and an anode and a solution. A charge is run through it and the copper is stripped off the penny and deposited on the other terminal. I speculated that this might be a way for us to mine copper from the zinc pennies and then we could still spend them, but there is not enough copper on them to make it worthwhile.
"Preserving coinage.. 2 tons at a time"
HoardCode0.1:M48/14USCA:US1Cu639700:US5Ni2400:CA5Ni46 |
|
|
|
n/a
deleted
26 Posts |
Posted - 04/22/2007 : 21:43:47
|
Simple,
I put them in a Rock tumbler.
24 - 48 hours with medium course grit to take the copper off,
then again with polish if you want them sorta shiny again.
Keep using the same course grit over and over, and it will have a lot of copper in it after a while |
|
|
|
n/a
deleted
59 Posts |
Posted - 04/22/2007 : 22:24:39
|
Huh. How's the condition of the coin after that?
-------------------------------------------------------------------------------------------------------------------
One of the chief attractions of the life of the wilderness is its rugged and stalwart democracy;
there every man stands for what he actually is, and can show himself to be.
-- Theodore Roosevelt |
|
|
|
n/a
deleted
59 Posts |
Posted - 04/27/2007 : 19:36:34
|
You may want to investigate this coin further. According to this site (You must be logged in to see this link.), pennies without the copper plating do exist and are valued at ~$100 (scroll to near bottom).
-------------------------------------------------------------------------------------------------------------------
One of the chief attractions of the life of the wilderness is its rugged and stalwart democracy;
there every man stands for what he actually is, and can show himself to be.
-- Theodore Roosevelt |
|
|
|
just carl
Penny Hoarding Member
USA
601 Posts |
Posted - 04/27/2007 : 21:30:40
|
quote:
Originally posted by HoardCopperByTheTon
I have found a few of those as well. My theory on how it is done is through electrolysis. Sort of the opposite of the way coins are plated in silver and gold as novelty items. There is a cathode and an anode and a solution. A charge is run through it and the copper is stripped off the penny and deposited on the other terminal. I speculated that this might be a way for us to mine copper from the zinc pennies and then we could still spend them, but there is not enough copper on them to make it worthwhile.
"Preserving coinage.. 2 tons at a time"
Your absolutely correct. That is just one method used in chem classes.
HoardCode0.1:M48/14USCA:US1Cu639700:US5Ni2400:CA5Ni46
Carl |
|
|
|
just carl
Penny Hoarding Member
USA
601 Posts |
Posted - 04/27/2007 : 21:33:05
|
Note that electrolysis in reverse is normal method to remove the Copper. Also, different acids react with different metals in different ways. For example Sulfuric or Sulfurous react much better with copper than many other metals so that is just one more method.
Carl |
|
|
| |
Topic |
|
copperplated-less zinc pennies
Forum Locked
