Wood burning stoves consist of a firebox (in this case a used barrel in good condition, the type with permanent ends with only a pair of bungs to add or drain the contents), a door to add wood and/or regulate the supply of air to the fire, legs to support the stove and keep it off the floor, and a collar to which a stovepipe connects to vent out the smoke and combustion fumes. Kits supply the additional parts except for the stovepipe.
Kits come with brackets and legs to support the barrel horizontally, a door with adjustable vents to regulate the amount of air entering the stove, and the collar and flange to which the stovepipe will be attached. All of these parts will bolt onto the barrel.
Instructions that come with the kits will show the exact place and dimensions of the door hole and exhaust port that need to be cut in the barrel. To cut the barrel and attach the parts you will need a drill and bits, a saber saw or jigsaw with hacksaw blades, a tape measure and grease pencil, simple hand tools, work gloves and protective eye gear.
The metal from which 55 gallon drums are made is easy to drill and cut. Use a marker to outline the holes to be cut, drill a starter hole large enough to fit a saber saw blade and cut along the mark with the saber saw. Hacksaw (metal cutting) blades wear quickly and are prone to breaking so expect to use two or three before you are done.
Once the openings are cut, position the leg brackets, door and flue-flange, mark the holes for the bolts and drill these holes. Attach the parts with the bolts that come with the kit, connect the stove to a chimney, and the stove is ready for use.
The first time you build a fire in the stove, the paint on the barrel will smoke, blister, char and may burn or chip off. Have doors and windows open and spread a tarp on the floor around the stove to make cleanup easier.
Lining the bottom of the stove with firebricks will extend the life of the stove considerably and will hold heat for a period after the fire burns out.
Though the vents on the door will allow you to adjust the amount of air getting to the combustion chamber and thus how fast the wood burns, a damper in the stovepipe between the stove and chimney will allow you to adjust the exhaust to regulate the amount of heat escaping up the chimney.
Flat stove tops that attach to horizontal barrel stoves are available. These allow barrel stoves to serve as cook stoves.