The Crazy Cool Can-Cup (Aka; how to turn a pop can into a cup)

How to turn a pop can into a cup.

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Step 1: What you need

You need:

a can
a can opener

Nosnazeb says: May 16, 2011. 3:10 PM

Awesome! But I wonder if there is a way to (economically) replace the thin layer with a thicker, more permanent layer to seal the aluminum. Normally I would not care, but currently there are Thor Dr. Pepper cans, and I'd love to have a set as cups, but later it will not be possible to get more with Thor in them to replace... any ideas on making a more permanent sealing layer?

dodo91 says: Mar 31, 2009. 5:52 PM

you might want to sand it. on a can, even though it seems safe, it can still cut. i woudnt try to drink from it.

parkerreno says: Sep 16, 2010. 3:36 PM

Did you make one? I just did, and if you get the opener in there just right it comes out perfectly without one sharp surface!

HADJISTYLLIS says: Jan 7, 2010. 8:03 AM

use this as mufler tip

stephenniall says: Apr 27, 2009. 10:39 AM

Very nice I suppose sanded down Painted you could definetly make some nice drinking glasses with these (sterilizing it first lol)

HIGHVOLTAGE-Z says: Jul 10, 2007. 6:51 PM

dont use the can to long because the can slowly loses it's sterilazaiton. not clean

MDude says: Oct 21, 2007. 5:54 PM

So why couldn't I just clean it? Is there anything in cans that degrades/dissolves I should be aware of?

HIGHVOLTAGE-Z says: Nov 5, 2007. 7:14 PM

Im not quite sure. i just showed this to my doctor friend s and thats what they said.

MisterSlippy says: May 17, 2008. 1:15 PM

It's not sterilisation that's the problem. It's the can itself. To prevent the aluminium in the can from leeching into the contents, drinks and food cans are coated with a layer of plastic or varnish. By removing part of the can, you expose the boundary of this coating, creating an area where liquids can penetrate the interface between the coating and the can. The coating seperates and breaks apart with repeated use, exposing the metal of the can to your drink. Not good. (information courtesy of the canada film board, lol) Generally it's a bad idea to consume metals in any quantity greater than the traces found in your everyday diet.

harley_rly says: Jan 17, 2009. 2:22 PM

I've always read that it was an oxide layer that forms on aluminum, after a couple of hours, that keeps it sterile and safe to handle.

threecheersfornick (author) says: Jan 18, 2009. 11:09 AM

Fascinating. I now have no idea who to believe.

Gorfram says: Mar 16, 2009. 12:17 AM

Okay, there are three different things that could be going on with the can-cups over time: 1) The way Nick has cut the can leaves the little folded rim in place over the sharp edge at the top of the can. That's good so far as not cutting your lip, but what it's not so good for is being easy to clean. Little eensy-beensy foody bits (and bacteria) can sneak in under the the edge of the folded rim and be difficult to get out - this is probably the sterilization issue that hV-Z's doctor friends were thinking of. However, if you immerse the rim of the can in boiling water, rubbing alcohol, or hydrogen peroxide - or just run it through the dishwasher - between uses, it should be about as sterile as any of your other dishes. b) Harley and Mr. S (& the Canadian Film Board :) are both right. There is an oxide layer that usually forms on the surface of aluminum whenever it's exposed to of oxygen (in just a few seconds). But this oxide layer can't form itself in the presence of acidic liquids like fruit juice (or, say, diet Coke :). So food processors put the thin coating layer that the CFB told Harley about on the inside of almost all food cans. Since Nick didn't remove the little metal rim, he wouldn't have affected the coating anywhere but on the rim itself (and normally, the liquids will only be contact with that rim while he's actively drinking them, and not during the whatever time elapses between sips). But just being exposed to air and light will tend to weaken the coating, not to mention wear and tear from normal use as a cup. And, while I don't know exactly what the cleaning methods I suggested would do to it, I wouldn't expect them to do the coating much good. If you leave water or milk in the can-cup overnight, and it has an "off" or metallic taste in the morning, it's time to retire that can from kitchen use. iii) But --- Mr. Quadruple-Oh-Seven (there sure are a lot of "Mr.'s" in this comment set) is right, too. The oxide layer that forms on aluminum is only a few atomic layers (about 3-5 or so) thick, and so fairly easily damaged. That's when the aluminum atoms can leach into your food or drink, potentially leading to all the nasty health problem he mentioned. My recommendation would be to use your-cup can until the novelty has worn off (or you notice any sort of metallic taste), and then either make it into something non-food-related or pitch it into the recycling bin. If you find you really miss it; then the time, trouble, and expense involved in making a new one isn't all that overwhelming. :) As to who you should believe - well, I do kind of sound like I know what I'm talking about. (There's not really any way for you to verify that I'm a Metallurgical/Mechanical Engineer (and did my Master's Thesis on aluminum) like I say I am; but, hey - you saw it on the internet, so it must be true :).

Mr00007 says: Jun 19, 2008. 9:20 PM

Yea, aluminum can be very bad. It is toxic, just like lead, even if it's just a small amount. If it gets deposited in the brain, it will mimic the symptoms of Alzheimer’s disease and osteoporosis. It can also impair kidney function. So it's just a good idea in general to stay away from aluminum if it's varnish has worn off, meaning once you drink a can of anything, it's probably best to get rid of the can.

jott_1 says: Nov 5, 2007. 6:49 AM

I have tried three different can openers. The top on the pop can is recessed too far for any of the can openers to reach it. What brand of can openers are people using?

tigerboy says: May 13, 2008. 8:11 PM

take it in your and and point it to the side of the can and continue to do that

threecheersfornick (author) says: Nov 11, 2007. 1:40 PM

Sorry for the slow response. My can opener is a Paderno. You don't have to get it very far in, just under the tiny crease on the edge. If you can get the can opener onto it far enough that it won't come off when you squeeze it, your good. I hope you can get it to work!

invent4life2234 says: Nov 19, 2007. 3:48 PM

great idea1! though i couldnt find out how to use a can opener and still get smooth edges so i just used a razorblade and it worked fine.

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sirskatesalot510 says: Jul 8, 2007. 5:16 PM

i have made a crossbow with a can its small but fun

threecheersfornick (author) says: Jul 8, 2007. 7:15 PM

Cool! Could you please explain how? (I want to try to make one :D)

sirskatesalot510 says: Jul 9, 2007. 12:07 PM

yah ive started making it as my first instructable

Patented says: Jul 4, 2007. 7:55 AM

good idea!

threecheersfornick (author) says: Jul 6, 2007. 1:05 PM

..which one? Lol.

akarimco says: Jul 3, 2007. 4:30 PM

Oh my god, I just figured out today that you can use a can opener to take the top off of a pop can, and then an hour later I'm seeing it on here... only difference is my goal was a bit more nefarious than yours ;)

Browncoat says: Jul 2, 2007. 11:07 PM

Sadly we've only got a hand-can-opener at this point, but we recycle our cans anyway. I'm now going to see how it works out to use that on cans! Here's hoping for not-sharp-edges!

threecheersfornick (author) says: Jul 3, 2007. 2:50 PM

That is a hand can opener. :P