Whether you're a gardener or just someone who cares about the environment, there's not much to dislike about composting. Compost enriches soil and can help remediate soil that has been damaged by pollution. By composting your kitchen scraps, you help reduce the amount of waste that winds up in landfills. Moreover, composting is easy to do. For many people, the lack of a suitable receptacle is the only hindrance to home composting, but it isn't difficult to make one of your own.
The Raw Materials
An old, 55-gallon drum is just the right size for a compost bin, but you need one that hasn't been used to hold toxic substances. You can often find one at a wholesale food outlet, because such barrels are often used to ship vegetable oil and other edibles. You'll need to cut an opening in the barrel so you can load it, so you should also buy hinges and a latch so you can close it and keep animals out of it. That's all you need for a simple composter, but if you want to make one that rotates, you also need some 2-by-4-inch lumber, a small amount of plywood and some 1/2-inch metal plumbing pipe.
It's important to turn your compost regularly to make sure the material is always exposed to beneficial bacteria and other microbes. The least complicated way to do this is to turn the barrel on its side every day and roll it on the ground. All you need for this design is a barrel with a top that you can fasten securely. You may, however, prefer the convenience of being able to spin the barrel around with an axle. You'll need a barrel with a latchable door on the side and an axle that can support the barrel on a frame.
A Basic Composter
To make a composter that you can roll on the ground, you simply need to cut off the top with a reciprocating saw. You should make the cut on the side of the barrel, about an inch from the top, to make it easier to attach the hinges and latch. Drill holes for the hinges and latch, which you will attach to the barrel with bolts and nuts instead of screws. To keep the compost aerated, you should also drill a series of 1/2-inch holes into the sides of the barrel. You can ensure proper mixing of compost by rolling the barrel for a minimum of three full turns.
A Spinning Composter
A length of 1/2-inch steel plumbing pipe will support a barrel full of compost, and you can insert it through pre-drilled holes in the top and bottom of the barrel. It's important to reinforce the plastic around the holes by gluing plywood to the plastic and drilling the holes through the plywood as well as the plastic. A structure composed of two Xs joined by braces at the top and bottom should support the barrel. To make a door, cut a panel out of the side of the barrel with a reciprocating saw and reattach it with hinges and a latch.