Aluminum Pop Cans

Most aluminum cola cans made in North America contain two different aluminum alloys. The can body is composed of aluminum alloy 3004 or 3104, whereas the ends of the can are aluminum alloy 5182. Aluminum 3004 contains approximately 97.8% aluminum, 1.2% manganese, and 1.0% magnesium (aluminum 3104 is very similar in composition). Aluminum 5182 contains 95.2% aluminum, 4.5% magnesium, and 0.35% manganese.

In addition, 3000 series alloys are heat treatable, whereas 5000 series are not, but work harden well.

Interestingly in Europe, a magnet will stick to the sides of an aluminium can.....strangely enough!! But not the tops.......

You can bet your butt it's not aluminium if a magnet sticks to it.

It looks like aluminium, my guess was some mixture of metals for cheapness.....

You may reference this website for additional information including a brief properties chart:

http://www.hschem.org/Laboratory/Flinn/Disappearing%20Aluminum%20Can.pdf

From the site above:

Most aluminum cola cans made in North America contain two different aluminum alloys. The can body is composed of aluminum alloy 3004 or 3104, whereas the ends of the can are aluminum alloy 5182. Aluminum 3004 contains approximately 97.8% aluminum, 1.2% manganese, and 1.0% magnesium (aluminum 3104 is very similar in composition). Aluminum 5182 contains 95.2% aluminum, 4.5% magnesium, and 0.35% manganese. As stated above, alloys in the 5 series are good at resisting corrosion. This explains why the ends of the can remain intact after the sodium hydroxide has eroded away the body of the can. The inside of the can is lined with a spray-on, water-based, inert polymer (i.e., plastic). The plastic is chemically inactive and has a greater resistance than aluminum against both acidic beverages and the basic sodium hydroxide used in this demonstration.

Plagiarism is bad...OK.

Thank You for the link.

It was exactly the information I was looking for.

Has anybody attempted to melt these in cans in a small foundry. What is your success? I am concerned about the paint on the cans becoming an issue. I would like to make some molds and do some testing.

Tom Cornell

You could burn the paint off first with hot air (about 450C should easily do it) then tumble with sand to scrub off the charred paint.

After a good wash to remove residual sand the cans can then be melted.

A flux introduced into the melt enables residual rubbish to be taken off as a slag. (NaF may do it, also a little lime. A bit of borax will probably also help. Don't use NaCO3 or caustic soda as they will dissolve Al.)

Try it out on a small scale first.

Sounds like a fun experiment.

Tom,

I would just let the paint burn off in the melt process The internal surface will have a food grade plastic film which will also burn off during the melt.

As the lid is a different metal, you may want to remove the lids and melt them separately......

As Travolta's character in "Phenomenon" said: "Let's be specific, Bob"...

Are we *ONLY* addressing "cola" cans (as even the linked pdf references)...? Or, do these alloys apply to the gazillions of beer cans lining the ditches on both sides of all roadways in the great bayou that is south Louizzy-anna?

And, does anyone have a link to Scotty's recipe for transparent aluminum, by chance?