I built a barrel stove out of a 35 gallon drum in H.S. shop class. Flat top, peanut butter jar lids for air vent covers that screwed in to close. Used a wire welder. My parents then used it to heat the small wall tent they lived in all winter in N. Idaho. The following spring, we moved them into a large, double-wall tent, built a floor, and they lived in that for another 4.5 years. Different stove.