A pig roast can feed a crowd of picnickers with relative ease; for many, a pig roast is the very epitome of summer. However, a pig can't be roasted on your average backyard barbecue. Instead, you'll need to craft a homemade pig roaster. The pig roaster need not be limited to roasting pigs: It can be used to barbecue large quantities of virtually any food. A few simple (though large) pieces of equipment can yield a portable pig roaster for use on any occasion.
Measure the diameter of the rod or shaft you've chosen to use as a spit.
Cut a hole in the center of each end of the drum cylinder: The hole should be the same diameter as that of the spit.
Saw the drum in half lengthwise. These halves will serve as the bottom and top of the roaster.
Designate one side of the roaster bottom as the back (it doesn't matter which side you designate as the front or the back). Attach two heavyweight brackets about a quarter of the way from each end using either rivets or welding equipment.
Measure the exact distance of the bracket placement on the bottom half of the roaster and attach the other side of the bracket to the exact same location on the top half of the roaster using rivets or welding equipment.
Drill holes into the floor of the roaster bottom for ventilation. The number of holes will vary depending on the size drum you're using, but as a gauge, for a 55-gallon drum, you'll want approximately 20 holes.
Cut a grate to fit into the roaster bottom. The grate will hold charcoal.
Bend a piece of metal sheeting to function as a handle and weld it in place on the roaster top. You'll also want a steel rod or pipe to prop the door open as needed.
Place the roaster on a frame. The frame can be any number of things. You might, for example, choose to mount the roaster on a trailer. Whatever your decision, the frame need only be made of a steel rectangle, which the roaster will sit in, and four steel legs to raise the roaster off the ground.
Fill the bottom of the roaster with charcoal.
Place the spit into the notches created in Step 2 and roast away.