I made a non-flat wood burning stove from a simple paint can. I got a 1 qt can, cut a square hole in the side of it, about 3"x3" or so, and drilled holes evenly spaced about an inch off the bottom. I got it to boil water by simply feeding pinecones to the flame. It worked great for the whole $3 I spent on it. If you make one yourself though, burn the inside plastic off, in a well ventilated area. Like outside. Get a good burn on it, about 20 minutes should burn everything off.