Metal drum barrels can be used to construct homemade barbecue grills, smokers and slow-roast cookers. A barbecue grill is the simplest design, as it only needs to use half of the drum barrel. When choosing a barrel, make sure that it was previously used to store food stuffs or harmless materials--don't use barrels that held old chemical waste or you risk contaminating any food cooked on the grill, with the possibility of serious health repercussions.
Cut the drum in half lengthwise with a jigsaw and metal cutting blade. Make sure the cut is as horizontal as you can make it. Select one drum half for your grill. The other half can make another grill, or be used elsewhere as desired.
File the cut edges of the drum with the metal file to smooth out and dull the edges, making sure that any jagged or sharp points are completely filed down to avoid injury.
Fill the drum half with combustible material, and light a fire inside. This cures the drum, and also gets rid of any residue from past substances stored inside. Newspaper and a bit of kindling should suffice.
Sit the drum half, open face up, on top of the metal trolley or table. Choose a trolley that is around the same length as the drum, and about 35 inches tall, to provide a good cooking height.
Drill four holes through the bottom of the drum, and through the trolley top, then bolt the drum down into the trolley through the pre-drilled holes. Drill two small holes on the ends of the drum, at the bottom, for ventilation.
Cut the metal grate with the jigsaw and metal cutting blade so that it fits inside the bottom of the drum, with about two inches of space underneath---this will sit the coals on top, with the underneath free for better ventilation of the grilling fire.
Evenly space the metal angle brackets, two on either side of the interior of the drum, so that the horizontal portion of the bracket extends out into the centre of the drum, flush with the edges. Draw in the screw holes of the brackets with the pencil, then pre-drill the screw holes through the drum at the points marked.
Screw in the brackets, then place the grill plate on top of the brackets, to finish your drum barrel barbecue grill.