Instructables

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

Step 2: How to make the cup

Remove the top from the can with the can-opener, just like you're opening a regular can. It's that easy! If you did it right, there shouldn't be any sharp edges.

Step 3: Ideas

Your done! That was easy!

Here are some ideas for other uses of this:
- cut a pattern into the can and make candle holders
- give away as presents
- chuck at your friends
- wear on your ears
- keep your salamanders organized

Okay, I'll stop.
Nosnazeb3 years ago
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?
dodo915 years ago
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.
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!
 use this as mufler tip
Very nice I suppose sanded down Painted you could definetly make some nice drinking glasses with these (sterilizing it first lol)
dont use the can to long because the can slowly loses it's sterilazaiton. not clean
So why couldn't I just clean it? Is there anything in cans that degrades/dissolves I should be aware of?
Im not quite sure. i just showed this to my doctor friend s and thats what they said.
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.
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)  harley_rly5 years ago
Fascinating. I now have no idea who to believe.
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 :).
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_16 years ago
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 jott_16 years ago
take it in your and and point it to the side of the can and continue to do that
threecheersfornick (author)  jott_16 years ago
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!
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.
C:\Documents and Settings\Owner\My Documents\My Pictures\2007_11_19\IMG_2824.JPGC:\Documents and Settings\Owner\My Documents\My Pictures\2007_11_19\IMG_2828.JPG
i have made a crossbow with a can its small but fun
Cool! Could you please explain how? (I want to try to make one :D)
yah ive started making it as my first instructable
Patented7 years ago
good idea!
threecheersfornick (author)  Patented7 years ago
..which one? Lol.
akarimco7 years ago
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 ;)
Browncoat7 years ago
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)  Browncoat7 years ago
That is a hand can opener. :P
mrbob10007 years ago
this is pretty cool! cut both ends and you have a cheap mini football kind of toy
threecheersfornick (author)  mrbob10007 years ago
Oh, and also, I just wanted to say: LINUX RULES!!! Thanks. (I'll be posting an instructable on how to switch to Kubuntu soon)
i have a kubuntu disk, i just cant switch from windows....it'd be too weird
threecheersfornick (author)  mrbob10007 years ago
Thanks! But... I don't get the football thing. Could you explain please? Thanks.