I've been playing around with making a soda can stove that burns 91% isopropyl alcohol, and after a few iterations I came up with a version that burns cleanly, albeit not very efficiently. I took a cue from Zelph's doodah-man special/ring-of-fire stove and used a fiberglass wick around the outside, and it burns cleanly when it has a pot over it. The construction is idiot-simple, just cut two cans (one smaller than the other) and drill a hole in the base of the smaller one. You pour the fuel down the middle, through the hole (after "wetting" the wick, if necessary). You can see in the second picture that I also cut some triangular slits in the bottom of the smaller can, to let the fuel seep out to the outside of the larger can. Then it's drawn up by the wick, and burns just above the stove. It weighs between 8 and 9 grams, my scale can't decide

Do you have any suggestions that would make this more efficient? It couldn't boil a cup of cool water with 3tsp (15mL) of fuel, although I don't have a very good pot so I just used a little metal bowl I got from the thrift store for a dollar . I bet a fancy titanium pot would boil quicker...