Introduction: Twig Stove
Here is a new stove project that allows you to cook food, heat water, make coffee, or heat a small lean-to with nothing more then small wood twigs, bits of bark and scrap wood. Instead of cutting logs and splitting fire wood, you use the usually abundant small stuff and brush found in the undergrowth to feed your fire. I can use an old pruning shear from my gardening tools and cut enough fuel to feed the fire in less then ten minutes, and cook 9 cups of coffee in 15 minutes! I'll even explain how to use other fuels and heat sources with this stove to expand on your options when using
Step 1: You Will Need:
1 - coffee can
1 - metal dog bowl or metal mixing bowel (Make the base of the stove and isolates from the heat)
6 - #10 threaded metal connectors (used to connect threaded rod) [hardware store item]
6 - screws (sized to fit the above connectors, I used #10 2-1/2" screws) [hardware store item]
1 - metal can bottom (just a bit smaller then the inside of your coffee can, (makes the burner plate)
1 - metal coat hanger (makes the bail or carry handle for the stove)
A step drill (Amazon) $15 (to use on many other projects as well!) Well worth the cost!
A Dremel Tool with cut off wheels (to cut the fire door)
Step 2: Step 2: Drilling the Air Inlet Holes
The holes in the can are as follows;,
16 individual 1/2" diameter holes in the bottom of the can (air inlets) located on the sides of the can, just above the bottom as shown in the photos. The bottom of the holes should be an 1/8" above the bottom of the can to keep the bottom joint unbroken and strong. The step drill was a joy here as it made the job of drilling these holes a matter of just about four minutes to do! (especially if you first use a sheet rock screw as a punch to the center of the holes so the drill self locates.)
Step 3: Step 3: Drilling the Vent Holes
Now we will drill the larger holes at the top of the can, the vent holes. Their purpose is to help vent the stove if a larger pan is used (which can make the stove burn at a lower rate if the exhaust gases can not escape easy.) These are 3/4" diameter holes located again, about an 1/8" below the top seam of the can. They are spaced as if 8 holes are to be drilled, but ONLY drill 7 holes. The missing hole creates a space here you can put the handle of your pot to allow it remain cooler so cooking is easier, and less chance of burning yourself. I usually locate this space directly opposite the fire door so as to make it easy to locate while cooking. Again, the step drill made this task, easy, especially if you first use a sheet rock screw as a punch to the center of the holes so the drill self locates.
Step 4: Step 4: Drill the Base (bowl)
Turn the coffee can upside down and place the metal bowl on it as if you were going to fill it with cereal. Now drill three holes around the bottom of the bowl as shown in the photo that will go through the bowl and the bottom of the stove. This now locates the bowl and bottom for adding the connectors later that will give the stove a cooler bottom, and make it less likely to burn the ground under the stove, (or even a wooden picnic table top as we found!)
Step 5: Step 5: Base to Can Assembly
Now we will assemble the stove parts to give us the unique shape and look that we want. First, we place the screws (3 of them) through the bottom of the coffee can (from the inside.) Next, we screw the connectors onto the screws until the can bottom is clamped between the head of the screw, and the end of the connector. Use a screwdriver and a wrench to tighten this joint.
Place the bowl bottom over the screws coming out of the connectors, and run a nut up the screw until it clamps the bowl against the connector and tighten. You will now have a wide stable base for your stove and an insulating airspace that will keep the heat of the stove from being wasted in heating the ground or even a wooden picnic table top! Remember that as this entire stove is modular, repair is easy and inexpensive.
Step 6: Step 6: the Fire Door
Break out the Dremel tool and put in a cutting wheel, its time to make a hole in the side to stuff your fuel in. I used a simple 2" wide by 2-1/2" high hole to allow stuffing in fuel, roughly centered on the side of the can, directly opposite where I left the blank space for the pot handle. Take the time to carefully file the door edges smooth, after all, its your fingers that will be near the edges and cut free is nice indeed!
Step 7: Step 7: the Bail or Carry Handle
Unkink a metal hanger and cut it to give you a straight wire. Figure out how much 'handle' you want, and then bend as shown. Drill two holes under the top rim just large enough to pass the wire through and sharply bend the wire over 180 degrees so that the handle flips over smoothly and doesn't hang up. Now you can move a hot stove with ease and safety.
Step 8: Step 8: the Burner Plate
This simple item is the heart of the system, and it is both vital and easy to make. Its purpose is to elevate the fire above the air inlets, and get air into the very middle of the fire. this insure a perfect burn, and HOT temperatures, (hot enough to boil 9 cups of coffee in just 15 minutes with twigs!) We take a small can top (or bottom), and drill three holes equally spaced around the edge for the legs we will create. Then we will drill a roughly centered pattern of holes (1/4" diameter) to act as the air feed holes that will insure clean burn and serious heat. As an indication of how well this works, note in the photo of the stove heating my coffee, that there is NO smoke, and serious flame taking place, indicating complete combustion. The can lid should fit as close to the size of the coffee can interior as you can get, but close enough is going to work here just fine.
Once you have the holes drilled, place a screw through each of the three "leg" holes and screw on a connector to create the stand off that will raise the burner plate above the coffee can bottom.
Step 9: Step 9: Painting
Buy a really good quality BBQ paint in whatever color suits your preference and paint your stove parts well. This protects the stove, and acts as a thread protector, and keeps the screws from coming loose as their heated. From time to time you will need to wire brush the stove and respray but that is easy enough and will protect your stove a long time.
Step 10: Step 10: the Grate or Grill
I used some cheap strap aluminum and cut the straps to around 7" long. Bolt them through the center of three straps, and bend the outer two straps to hit the can edges at whatever angle you like. File small notches so as to locate the grill on the can edge and the stove is complete. Simple and strong, and easy to replace when needed. (I have also used a heavy wire shroud from an old 12 volt auto fan to make a grill and it worked a treat, letting me grill a steak right on the grill, sweet!)
Step 11: Step 11: Other Fuel Ideas
This stove was designed to use multiple fuel sources and heat sources, and thus increase its usefulness to you be it for camping, an emergency, or heating a quick meal on the roadside on a day trip.
Alternative Heat Sources for the Stove
Twigs and small branch sections (stand them on end and light near the bottom of the fuel)
Charcoal Briquettes (just pile them in and light)
Small chunks of wood (once fire is going) I often use 2x4 cut offs from projects or from construction sites)
Sterno Can (set inside and happy heating)
Burner Buddy (tuna can filled with rolled cardboard and wax soaked)
A Nan Stove (see my other Instructable https://www.instructables.com/id/The-Nan-Stove/ )