How to tell if its aluminum or just plated

I have read a lot about the 1974 aluminum penny, but I can't find how much it weights or if there is a way to tell if its actually albumin or if its just a copper plated coin. People help : )

 

Log in or Sign up to hide this ad.

If it was a true aluminum coin it would be very light. You would know if it was aluminum. It it was copper plated with aluminum it would be pretty heavy and the size of the coin probably wouldn't match up with that of other pennies. A good way to test it put it in water. I think aluminum floats.

 

...i think the plastic ones float. :whistle:

 

It would be alot lighter, Both in weight and color!

 

I think i mite have an aluminum 1972 d penny

 

100% you do not.
If it truly has that color, it's been plated.
There are no 1972-D aluminum pennies.
Even the 1974 aluminum pennies that did exist at one time are illegal to own,
they were never issued as currency.
The last one was confiscated by the government, and they weigh less than
1 gram. You penny should weigh 3.11 grams.

 

nope. does not exist.

 

True, but if you place it on the waters surfaces VERY carefully you might be able to get the waters surface tension to support it. But that's not floating.

 

Although it is possible to aluminum-plate copper, I've never heard of an aluminum-plated copper coin. Typically, mints plate a more valuable metal over a less valuable metal core for obvious reasons. Has anyone heard of an aluminum-plated copper coin?

Cal

 

How about an aluminum plated 1933 gold double eagle?

 

It would be pretty easy to tell if a coin is aluminum, mainly because they are SO light.

 

The US mint did experiment with aluminum plated copper blanks for cents in 1916 and 1917 but nothing ever came of it.

 

But why? What would be the point of that...

 

I have no idea why they did it, I just know that they did.

 

When you plate a more active metal (like aluminum) over a less active metal (like copper), the active metal protects the less-active core. You get a more stable product. This is the rationale behind galvanized (zinc-coated) steel.

Zincolns do the opposite (more-active core, less-active shell). That's why they self-destruct once there's a hole in the copper layer.

The thing is, copper itself isn't reactive enough to need a sacrificial protective layer. Copper forms an oxide layer that's pretty stable. So I agree that it seems kind of pointless. Presumably the Mint came to the same conclusion. (Also, presumably, there was no lobby pushing for legislation to do it anyhow.)

 

Interesting, and I believe you. Are there any articles or documents on it?

Cal

 

It's not an aluminum plated coin.
If the coin is silver plated, nickel or mercury plated it will
sort of look like the color of aluminum foil.

 

I only have three, from documents I transcribed for Roger Burdette. Not much to them, just brief letters about the planchets, I believe where they were from and requests by one official to be sent examples for examination.

December 29, 1916
SUBJECT: Calorized blanks for one-cent pieces.
Superintendent, U. S. Mint,
Philadelphia, Penn

Sir:
Mr. Charles Rowe, of the General Electric Company, was in today and advised me that 30,000 one-cent blanks had been calorized and were ready for coinage.

As I understand it, they wish to have these blanks put through the regular processes incidental to coinage, and when these blanks are delivered to you I will be very glad if you will run them through the presses and store them away separately, sending me a supply here for examination.

Respectfully
H. F. von Engelken
Director of the Mint


January 8, 1917.
SUBJECT: Calorized blanks for one-cent pieces.
Honorable A. M. Joyce, Superintendent,
U. S. Mint, Philadelphia, Penna.

Sir:
Please refer to my letter of December 29th on the subject of calorized blanks for one-cent pieces.

When these blanks are delivered to you please hold them until Mr. Thompson, of the General Electric Company, has had an opportunity to consult with you relative to their past treatment and future working.

When you receive these blanks notify Charles E Rowe, Kellog Building, Washington, D.C., that they have been received, sending me a copy of your letter.

Respectfully
F. J. H. von Engelken
Director of the Mint


January 16, 1917.
SUBJECT: Calorized Blanks
Superintendent, U. S. Mint
Philadelphia, PA.

Sir:
Will you please forward to this Bureau about $3.00 in calorized cent pieces. The coins will be returned to you as soon as inspected.

Respectfully,
F. J. H. von Engelken
Director of the Mint


That's it. There may be more documents in the archives but that's all I have seen so far. I never know what Roger will send me.

 

Very interesting and thanks. I've never encountered the word "calorize" before. I'll have to work it into a conversation sometime.

Have any of the coins survived?

Cal