Your Inner Hobo

Building a DIY cook stove.

An ingenious little camp stove that doesn’t cost a dime? Sign me up. Using a few simple materials, you can build a fuel-efficient “rocket stove” — an updated version of the tin can “hobo stove” used by generations of wanderers, survivalists, and backwoods campers.

There are many ways to cobble together a cooker made out of tin cans, but the innovation that transforms a basic hobo stove into a rocket stove is an L-shaped combustion chamber that contains an insulated vertical chimney. This design reduces the amount of fuel needed; a tiny fire should provide enough sustained heat to prepare anything from a cup of coffee to a full meal, at least after you’ve experimented with the system a bit. A rocket stove also produces less smoke than a conventional cooker, and because it’s insulated, the outer surfaces stay cool to the touch.

To construct a rocket stove, you’ll need empty, clean cans (two 28-oz., and one #10 with lid), tin snips, marker, gloves, and insulating material such as pebbles, aluminum foil, or scraps of household insulation. You’ll also need a hammer and nail to punch holes as starting points for cutting the cans, and a wire coat hanger if you’d like a handle for the finished stove.

If you have a can of black, high-heat spray paint, keep it handy. With no skill base whatsoever, I was able to build a stove that looked reasonably okay once I gave it a coat of paint that disguised my jagged metal cuts.

Check the web for detailed rocket stove instructions with images — one good site is instructables.com. Be sure to follow the directions exactly so that the finished product has the right measurements to work well. To test your unit, lint from the dryer makes a great fire starter, and for fuel, use very small twigs or tiny amounts of just about any other flammable material.

A cover on your cook pot, and a “collar” around it (one centimeter distance from the pot), can create up to 50% more heating efficiency. You can make a lid and collar by cutting the correct-sized tin can, or by making them on the spot out of aluminum foil. You’ll find other important tips about fuel, positioning the fuel shelf, and feeding the fire on rocket-stove websites.

Building this cooker would be a great project to do with older kids, but you’re going to be surprised at how interested your adult friends are too. Expect a lot of comments and unsolicited advice. And expect a few of them to later confess they took a stab at stove-building themselves.