Here's a project I've been working on. Its a 55 gallon drum. It will be and almost is a smoker now. First thing done is a burn out. To burn and remove any pollutants inside of the barrel. You can use a drum lid, but to add space I am using a salvaged old Weber kettle lid. A little modification and rolling of the metal was needed to make it fit. I used some fork horn deer antlers that my friend left me to make a jackalope that I never got to do. And a fresh coat of high heat muffler paint. I then pressure washed the drum. We are still gonna sandblast the inside of it before I season and use it. Then I added a rack from an old gas grill and axle and tires to make it mobile. I added some 2" thick oak boards and a couple shelf brackets to make a table on it for digital thermometers beer ect... I stained them last night. I also added some hooks to the front of them for hanging grill tools. They have to be pretty well sealed, so I added some 2 part epoxy around the axles for an air tight seal. There are three levels for grates in this one. Made the holders from simply bolting stainless bolts through the side. I need two more replacement grates yet. But I havent got them.The air intakes at are at the bottom. There are 4 of these around the bottom. It's a stainless steel bolt with a spring and some flat steel to cover the holes. They have to have very sensitive air adjustments so as not to burn hotter than 250-300 degrees. This allows it to cook for upwards of 10 hrs on 9 lbs f charcoal in one fill. The fire box is a salvaged grill grate with a box made of expanded metal lath. This will be mounted 3" off the bottom inside to hold coals. I still have to put a water pan in this too. This is where it sit's now. It has three hooks under rack for mopping brushes. and a beer can chicken holder hooks under the table. Oh and I installed a thermometer on the lid to manage temperatures. I even put a brass frog on the lid.