I recently came across some plans on the internet for a pop can alcohol stove and knew I had to try it. It's the kind of stove that you can use on a backpacking trip. It's made entirely of pop cans, so it's cheap (especially if you're a pop drinker) and extremely light weight.
There are many different designs out there, and they all have their merits. After many attempts I've come up with a design that works for me and is easy to explain to others. And, after all these attempts it's time to stop building them for awhile because Annie wants her kitchen table back.
What you'll need:
2 pop cans (empty)
4 more pop cans (also empty), for when you make a mistake
A utility knife
A drill with a small drill bit
A ruler of some sort, or just a good eye
A metal file is helpful, but not entirely necessary
A supportive wife
There's a good chance I forgot a few things in the list. When you see them mentioned below, just mentally add them to your own list.
I like to start with the parts most likely to go wrong first. The very first thing you'll want to do is drill a big hole in the bottom of one of the cans (didn't I say you want a 1" hole saw bit?) A hole saw on a drill is the easiest way to go, since the bottom of the can is pretty thick, but you can use other things to make the hole, too. However you make the hole just be sure to either (a) file the edges so you don't cut yourself, or (b) be careful not to cut yourself.
After you drill the big hole wrap some masking tape around the bottom of the can (did I mention masking tape?) and mark both ends where they cross each other. Then remove the masking tape.
Don't worry, you put the tape on for a purpose. Lay the tape flat on the table and with the ruler (I know I mentioned the ruler) divide the tape in half, then in half again. That will give you four marks (the two at the ends are in the same place on the can). From there you can decide how many holes you want. I've seen anywhere from 6 to 32. If you have a small drill bit go for more holes. If your drill bit is a bit bigger go with a smaller number. Chances are pretty good that after you finish this stove you'll drink a little more to make a couple more stoves and you can try different hole patterns on each of them.
Put the tape back on the can and drill holes at each mark. I like the holes right in the center of that angled surface on the bottom, as seen above. You can go to the far outside, or right up near the rim if you'd prefer. I don't know which is better. The only thing I can tell you for sure is that all your holes need to be in the same ring around the can so that they end up at the same height. If some holes are significantly higher than other holes they won't get as much fuel coming out of them.
In this example I did large and small holes just for fun. I don't think it makes it any better or worse, just different.
The next step is to get out the tape again. Make a mark or two (or four) 1 1/4 inch from the bottom of the can and wrap a piece of masking tape around the can at that mark (on the bottom side of the mark, as shown above). The nice thing with the tape is that it tells you if you went straight around the can or not when you get back around to where you started. If it doesn't line up exactly, re-wrap it.
Get out your utility knife (I've heard you can even use scissors for this, but I didn't want to risk further aggravating Annie in case it has a dulling effect). However you choose to do it, cut as close to the tape as you can all the way around the can. Once you have it separated, cut tabs in the can as shown below to allow this part of the stove to fit inside the other part.
You didn't throw away the rest of the can, did you? We're going to use every part of the buffalo for this project. Cut the can all the way around near the top to give yourself a section of can at least 1 5/8 inches tall, then split the section so it folds out as shown below.
You'll want to cut the piece to 1 5/8 inches tall, and maybe hack a 1/2 inch off the end. Then roll it up and set it in the stove top piece you've already cut and push it down into the lowest part of the stove top piece. Make a mark where the pieces cross, then cut halfway through the piece on each end (from opposite sides, as shown) so that the two ends can be inserted into each other to make a loop.
There are two ways to connect the two ends. I like to put the tabs on the inside rather than the outside so it stays a little more round. Plus, it just looks better. Before you make a loop out of this section, you'll need to cut three notches on one side or the other (all on the same side). I usually cut a notch right in the middle of the piece, then measure out both directions 1 7/8 inches and make notches there.
Next we'll make the bottom section of the stove. It's a lot easier than everything else. Just measure up 1 1/4 from the bottom of the other can and put tape around it, just like you did for the stove top. I like to put a lot more tape (2-3 times around the can) and leave it on when I push the two halves together. It probably doesn't give the aluminum any additional strength, but I like to think it does. If nothing else, it makes it a little easier to grip the can.
Once you've cut out the bottom you should have something that looks like this:
Now just put the stove top inside the stove bottom. Make sure the notches on the center piece are on the bottom (they're there so the alcohol can flow freely, not so the air can flow freely).
This, at least for me, is the hardest part. Try to push it together evenly. If you're even a little bit tilted it will buckle and tear the bottom part. There are many theories about how to make this part easier. None of them work. Really. It just takes patience, persistence, and an unexhaustible supply of pop cans.
But when you finally get it together, it looks a lot like this:
If you don't have any laying around the house, go to the paint section of the hardware store and pick up a can of Denatured Alcohol. Pour a bit into the center section of the stove and light it.
It will burn in the center for a little bit. Maybe a minute or so, depending on the temperature and other factors. At a certain point, though, the flame will move out to the burner holes on the side.
When the alcohol in the middle is burning, it's heating up the rest of the alcohol. As the alcohol heats up, it expands and vaporizes. The inner wall you built traps the alcohol vapor in the outer section and it has nowhere to expand but out the holes. The stove will continue to pressurize itself through its own heat until the alcohol burns up completely.
There are a couple other things you can do to make the stove a little more functional. With a third can (get digging through the garbage again) you can cut off the bottom 3/8" and use it to put out the fire by setting it on top of the stove. That will cut off the oxygen supply and the fire will go right out. You can also make a "simmer ring" to limit the heat of the fire by cutting out the top 3/8" of a can and setting it on top. The fire will be limited to the hole that you normally drink out of.
Anyway, hopefully this is a project you'll at least attempt. It's a lot of fun, and a bit addicting. Just try not to burn the house down (I'd seriously recommend only using these outside. They can really burn hot.)
