I am just about finished with my first smoker build and it is ready for action this Labor Day. Can't wait to fill it with meat! I've never done a lot of metal work prior to this so I ended up with some things that are not straight, or level and I did a lot of grinding on some ugly welds. All in all I am very happy with the way it turned out. The trailer is from an old pop-up camper I tore down and scrapped. The cooking chamber is an old air tank. I cut off the top plate and cut a single door into it. I wanted it to have a large enough opening so I could get a whole hog into it. The handle, shelf, counter weight and stacks are made from pipe and scrap I had laying around the shop. I did buy the 2"x2" tubing that supports the tank, the grating sheets, some 1 1/4" angle and the 2" flat stock that is around the doors. All total I have about $400 dollars into it. The cooking chamber and fire box are welded to the support underneath but the whole thing is bolted to the trailer so I can move the whole thing to another trailer or mount it to something else in the future without having to grind a bunch of welds. The fire box is made from an old 100 gal. propane tank that I shortened. After I shortened the tank I did find a few smoker build calculators online. A couple of them calculated that my fire box was only about 80% the size it should be for the size of the cooking chamber but I have burned some fires in it and my cooking chamber reaches over 700 degrees very easily and I can maintain 200-300 degrees so I think it will be fine. I cut air holes in both sides with adjustable dampers to make sure I have plenty of air flow. I placed a damper at the fire box to cooking chamber opening for more control. I figure you can never have too much control. I cleaned and coated the entire inside of the cooking chamber with Crisco to season it and keep it from rusting. Same idea as a cast iron skillet. Tonight I will light it up and complete that step. Labor Day I plan to fill it with meat for it's virgin smoke. There are still a few things yet to do like add fenders and do some more work on the floor grating. I also want to make sliding lids for the storage cage that when slid out will create a table on both sides of the smoker. I also have a large burner I want to mount as well as a mount for my tap system. It will make a great tailgating and BBQ competition trailer! The old brackets that were used for support poles on the pop-up will also make great flag pole mounts. I also plan to mount supports for some type of canopy or umbrella for shade on those hot Texas days. I plan to start a BBQ business at our RV Park called Backyard BBQ and this is the first step. I also have a 1967 Airstream trailer I plan to convert into a kitchen. That is the next project.