Coin Community Family of Web Sites
Like us on Facebook! Subscribe to our Youtube Channel! Check out our Twitter! Check out our Pinterest!
Username:
Password:
Save Password
Forgot your Password?


Welcome Guest! Need help? Got a question? Inherit some coins?
Our coin forum is completely free! Register Now!

1995 Lincoln Memorial Incomplete Plating

First page | Last 15 Replies
 
To participate in the forum you must log in or register.
Author Previous TopicReplies: 24 / Views: 740Next Topic
Page: of 2
Pillar of the Community
Learn More...
United States
1189 Posts
 Posted 05/18/2022  5:22 pm  Show Profile   Bookmark this reply Add Cujohn to your friends list Get a Link to this Reply
Silviosi, Thank you for straightening me out. So this was an old way of drying out planchets? Would this be a way they were burnished? I've also read that the electroplating will build up on the edges and corners. Could this be why the center of the planchet received less plating?
Pillar of the Community
Canada
2404 Posts
 Posted 05/19/2022  5:26 pm  Show Profile   Bookmark this reply Add silviosi to your friends list Get a Link to this Reply
@CUJOHN: I will answer you quoting the metallurgical compendium:


Quote:
The anode is connected to the positive terminal and the cathode (metal to be plated) is connected to the negative terminal. Both are immersed in a solution that contains an electrolyte and connected to an external supply of direct current. When DC power is applied, the anode is oxidized.

Metal atoms dissolve in the electrolyte solution and ions are reduced at the cathode forming a coating. The current through the circuit must be adjusted so that the rate of the anode being dissolved equals the rate at which the cathode is plated.


I will add: The ability to cover plating uniformly is called throwing power. The better the "throwing power" the more uniform the coating.
Edited by silviosi
05/19/2022 5:27 pm
Pillar of the Community
United States
2998 Posts
 Posted 05/19/2022  6:57 pm  Show Profile   Bookmark this reply Add Petespockets55 to your friends list Get a Link to this Reply
Cukohn is correct.
This is the video of the plating process from the old Jarden Zinc who produces the Lincoln cent planchets for the US mint.

Silviosi, it is not a drying system. If you look at the top of the rotating drum you can see bubbles on the surface of the liquid at the top of the screen.
I believe the title of the video refers to 45 RPM (Revolutions Per Minute) and the flexible "German Hand Grenade" like object rotating with the planchets.

From CC archives.
http://goccf.com/t/350002
Words of encouragement are one of the major food groups.
We need to consume them regularly to thrive and grow.
Edited by Petespockets55
05/19/2022 7:05 pm
Pillar of the Community
Canada
2404 Posts
 Posted 05/19/2022  9:18 pm  Show Profile   Bookmark this reply Add silviosi to your friends list Get a Link to this Reply
Pete: I will put you here the patent of the Standard Dangler:
https://patents.justia.com/patent/6656606
Pillar of the Community
Learn More...
United States
1189 Posts
 Posted 05/20/2022  5:20 pm  Show Profile   Bookmark this reply Add Cujohn to your friends list Get a Link to this Reply
Thanks Pete I went back and watched that video again. I didn't see it before, you are right you can see the air bubbles at the top. They are tumbling through the solution. Somehow they are connecting the anode and the cathode inside the drum.
Pillar of the Community
Canada
2404 Posts
 Posted 05/20/2022  8:05 pm  Show Profile   Bookmark this reply Add silviosi to your friends list Get a Link to this Reply
@CUJOHN : Inside of the plating you will never see bubbles. Why, simply if are bubbles are mean it is oxigen there which will react with the solution. Sorry contradict you.
Pillar of the Community
United States
2998 Posts
 Posted 05/20/2022  11:03 pm  Show Profile   Bookmark this reply Add Petespockets55 to your friends list Get a Link to this Reply

Quote:
Pete: I will put you here the patent of the Standard Dangler:
https://patents.justia.com/patent/6656606


Thanks for the link Silviosi. That "Dangler" is used for elotroplating aluminum blanks?
For those interested the link starts out discussing how difficult the plating process is for getting metals to adhere to aluminum. It goes on to discuss coinage being used today.

Here are a couple of selective quotes from the link:
".... The pretreatment and electroplating steps are preferably conducted by barrel plating, in accordance with another aspect of the invention.... "

This quote indicates electroplating is done by "barrel plating".

".... A particularly difficult environment for electroplated products is circulation coinage. Today, many countries of the world rely on plated coinage in which coinage metals, such as nickel, copper, bronze or brass overlayers are electroplated onto cores of coinage metals such as zinc, steel, or nickel. ..."


"Processes of electroplating such coinage cores have been developed to ensure that a highly-adherent electroplated layer is formed which can withstand a bend test. The bend test is one indication of whether the plated coinage product can withstand the rigors of a deforming process, that is a minting step, without delamination of the electroplated layers from the substrate. While bend tests may vary, in general, to pass such a test for circulation coinage, the plated coin blank is bent through a 90 angle and the plated layer must not be removable with a sharp instrument such as a file or knife. Although aluminum and its alloys have been used in coins, to the inventors' knowledge, no electroplated circulation coinage products with aluminum or aluminum alloy cores exist in the world today. Efforts by the inventors to apply a simple zincating solution, or an MAZ solution to aluminum substrates, as set out in the Examples of this application, failed to produce adequate adhesion to pass a bend test."
Interesting info about using a bend test to confirm proper adhesion of the finish metal to the substrate.



Quote:
... Inside of the plating you will never see bubbles. Why, simply if are bubbles are mean it is oxigen there which will react with the solution....



If the video isn't a demonstration of the plating process for the zinc blanks can you tell us what the video is showing?

Words of encouragement are one of the major food groups.
We need to consume them regularly to thrive and grow.
Pillar of the Community
Canada
2404 Posts
 Posted 05/20/2022  11:43 pm  Show Profile   Bookmark this reply Add silviosi to your friends list Get a Link to this Reply
@Peter, You understand me very well. You know this complicates steps. The drum which you see in the video was use in time for plating preparation. In order to plating you has to prepare the material. You understand thee phenomena of plating and adhesion of ions to an materials, so I do want to go there.

PS: Standard Danglers was never use be mint. The principle Yes.
Edited by silviosi
05/20/2022 11:46 pm
Pillar of the Community
United States
2998 Posts
 Posted 05/21/2022  12:29 pm  Show Profile   Bookmark this reply Add Petespockets55 to your friends list Get a Link to this Reply
Thanks Silviosi.

I agree the Dangler was never used at the mint. The video was from the firm that makes the Lincoln cent planchets and ships them to the mint.

That video was originally from the old Facebook page (2016?) for Jarden Zinc. I can't remember what was mentioned about the video since the new private equity firm that bought out Jarden Zinc "cleansed" the info on the site. (The video is a hard find when searching.)
Words of encouragement are one of the major food groups.
We need to consume them regularly to thrive and grow.
Page: of 2 Previous TopicReplies: 24 / Views: 740Next Topic  
 
To participate in the forum you must log in or register.





Disclaimer: While a tremendous amount of effort goes into ensuring the accuracy of the information contained in this site, Coin Community assumes no liability for errors. Copyright 2005 - 2022 Coin Community Family- all rights reserved worldwide. Use of any images or content on this website without prior written permission of Coin Community or the original lender is strictly prohibited.
Contact Us  |  Advertise Here  |  Privacy Policy / Terms of Use

Coin Community Forum © 2005 - 2022 Coin Community Forums
It took 0.28 seconds to rattle this change. Powered By: