Fill the propane tank with soapy water and allow it to sit for at least two weeks.
Cut a hole in one end of the tank, using a cutting torch. Do not empty the water from the tank before cutting this hole. The water will provide a level of safety should any propane or fumes remain in the tank. Allow the water to drain from the hole.
Blow-dry the inside of the tank with a commercial-grade fan or air compressor for at least half an hour.
Remove all of the rounded end you previously cut a drain hole in, using a cutting torch to cut along the factory seam.
Build a firebox on to the cut end of the tank, using 1/4-inch sheet metal or a sheet metal that matches the thickness of your tank's walls. The firebox houses the fire that smokes the meat. To assemble the firebox, cut three rectangles 16 inches tall, and the same width as the cut end of your tank. The fourth side of the box should be a circle the same diameter as the open end of your propane tank.
Weld these four pieces together to form the sides of a box. The rectangles should be welded as close to the bottom of the circle as possible, without having any edges overhanging. Cut a bottom and top for the box. Weld the bottom to the four sides. Use two welded hinges to attach the top to the box. This will serve as a lid, through which wood can be placed in the smoker.
Install a damper into the top half or the circular end of the firebox. A commercial damper, like one used on a woodstove, can be installed. To build your own damper, cut a square hole into the circular end of the firebox. Weld two sections of track to the top and bottom of the hole. Cut a piece of sheet metal to serve as a sliding door, and slide it into the track. Affix a handle for ease of use.
Weld the firebox to the end of the smoker that was previously cut. The circular side of the box should be welded into the cut end of the smoker, with no gaps.
Mark the door of the smoker with chalk. The door should be 3/4 the length of the tank, not including the firebox, or rounded end, and should have a height 1/4 the tank's circumference.
Split the marked door to create two doors of a more manageable size. First, mark the center of the door. Then draw two lines 3 inches out to each side of the center mark. This puts a 6-inch brace between the two doors, and makes two smaller doors in the smoker. This will both allow better control of heat loss when the lid is lifted, and make the doors lighter and more manageable.
Cut along the top chalk line of the first door; do not cut around the sides. Weld the hinges into place on both the tank and the door, then cut the other three sides loose. This will ensure that the door does not warp as it is cut. Repeat this process for the second door. Affix handles to each door as desired.
Cut a hole with a 6-inch diameter into the top of the tank. This will serve as the opening for the smokestack
Slide a 6-inch piece of stove pipe into the hole. Weld the pipe to the smoker or leave it loose, with a joint section of pipe intended to be slid inside the opening on a commercial stove.
Cut four sections of pipe, all the same length, to serve as legs on your smoker. The height of the legs will determine the overall height of the smoker. A trailer can be used as the base of the smoker rather than putting it on pipe legs, which will also make the smoker more portable. If pipes are used, they should be well-braced to ensure that they can support the weight of the smoker.
Cut grill racks to set inside the tank. The grills should be roughly the same width as the propane tank's largest point, so that they will rest on the bottom curve of the tank as it begins to narrow. They should be cut in lengths that can be easily inserted through the smoker doors.
Things You Will Need
- Cutting torch
- Grilling rack material
- Sheet metal
- Stove pipe
- Air compressor
- Ideally, use a propane tank that has never contained propane.
- A thermometer can be installed in the center of the tank, in the branch between the two doors for heat monitoring purposes.
- A damper can be installed in the smokestack.
- Propane tanks in good condition work better for smoker construction. A tank that already demonstrates signs of rust will have a much shorter life as a smoker than one with metal that has not yet begun to deteriorate.
- Paint the outside of the stove, ideally black. Stove black is available from most hardware, paint and building supply stores and is intended to withstand high heat.