Stand old fuel tank on end. cut out most of the bottom so you can lifit it up to dump the ashes.leave 3 inches or so around the edges of the bottom, to make it stronger. ( fill tank with engine exhast or co2 before cutting) research how to do that elsewhere)
cut a vent hole or 2 in the side (but at the top end)(not top) to set the smoke out. (A hole in top lets rain in and gets everything all soggy and makes tank rust outmuch faster.)
cover vent holes at top with expanded metal to keep the floaters in.
cut some vent holes low to let air in
cut a door hole and hinge it, and a latch, don't worry about it letting in air, gota get some in somewhere.
