Roberto,

Your ski camping buddies from Manitoba have been using these for 10 years. On oru last winter camping trip, you were too busy doing quality control sampling on the brandy supply to notice we were melting snow for drinking water using a pop can alcohol stove. I've probably made 30 or so of them over the years, one thing for certain you can make 10 of them in exactly the same way and some will be much faster to the boil than others. My favorite is made out of 2 pizza sauce tins(not aluminum so it's a little heavier), it burns gangbusters and boils water faster than any stove I've made since, forget about simmering with this one it's just a rocket.

On slow nights in the lab over the years I've used a laser themometer and tested a bunch of designs. It seems the smaller you can make the burner holes the faster it will bring water to a boil. I punch 3 small holes in the concave bottom of the can used for the burner and use those a fill holes rather than punching a large fill hole, and lots of really small holes in the rim of the can used for the burner. I think as the can heats, the alcohol boils, and pressurizes the vaporised alcohol to a degree, causing more heat output. Ethanol works best and you can drink your stove fuel in a pinch :) Just don't confuse you naptha and your ethanol!

Ken