Ahhhhhh, the Rocket Stove. What more can I say, well actually quite a bit. The key elements of the rocket stove are the L-shape design, insulation of the main chamber, and the Fire Triangle .
That is it.
With the hundreds of plans, video's, websites, etc. out there talking about rocket stoves, I decided to give it a go and build one, or actually 3.
The first two were prototypes or to be honest, what I like to call my trial and error attempts. I have seen several designs both large and small that I liked, but I wanted something more portable, something with multiple uses if possible than just a stove (I like to carry items that are multi-purpose or multi-use whenever I can), so I decided on a version I saw using a #10 steal can.
The good- It is incredibly efficient, fast heating, low smoke, temperature adjustable, very simple to build and the size I made is easily transportable and multi-use
The not so good- the smaller the stove, the more futzy it becomes. Even though it is efficient, you will be feeding it constantly to assure maximum heat output is maintained. Also if you do not have smaller sticks and twigs, then you will spend time processing larger logs down to fit into the feed chamber.
*Disclaimer boilerplate: I will say right now, that I am not the originator of this idea, and lay no claim as to inventing it. However, the photo journal below is the step by step process of myself making my own DIY Rocket Stove. End legal disclaimer.*
I decided on a 1 gallon paint can as the main container of the stove. The whole thing can be packed into itself and you can use the excess room for your fire starting kit, cook kit, spices, tinder, etc. If you use some aluminum flashing tape or hvac duct tape you can seal the side hole in the paint can, and with the handle still attached, use the can as a water tight container.
The feed tube is a 15oz cream of corn can, any can this size will do, just make sure to get the kind with the metal rings on the top and bottom. The rings will stay in place after removing the top and bottom, and will help to reinforce the can. For the stove heat/cooking stack, I used a 24oz spaghetti sauce can, and for the feed/draft plate I used another can, size isn't an issue as long as it will span the width of the feed tube.
Illustration 1: Both ends removed for the feed tube
Illustration 2: rotate the can to get your circle
Step 1: Assuming you've already eaten the contents, remove the bottom of the small 15oz can. (marked with an "s" in photo above.) You will want to use an old style can opener. This keeps the sealing rings intact. The new openers remove part of the ring and you have a clean edge but a weaker can. I left the bottom on the stack can for strength and support, and if you only have wet sand or dirt to fill it with at camp, it will give you a dry bottom initially for your fire.
Illustration 3: measuring the "Stack" can
Step 2: Measuring and marking your cans for cutting. Use each can as your pattern and mark with a permanent marker. It might not be a perfect circle, but if you hold the can with your thumb and index finger and carefully rotate it to the left, mark it, then right, and mark it, you should get close. When you look at the pattern it will have an oval shape. That's normal, its an optical illusion. I measured the top of the stack just below the rim of the paint can. This allows room for the lid if you are going to leave it assembled and carry it.
*Ah Nuts* : Make sure to place your holes on the opposite side of the seam. When the can heats up the metal can expand and if the whole is cut over the seam like my first trial you will have a nice open sided can!
Step 3: Cutting your cans. Using tin snips, carefully cut out the hole. If you make a pilot hole first with a 3/8 drill bit or larger, it makes it easier to start the hole. Also, if you cut just to the inside of your pattern where you drew your lines, it will get you close. See illus #5 Then you can nip away as needed to get a good fit.
Step 4: Fitting the cans: after cutting and trimming the holes, place the feed tube inside the paint can and insert it from the inside out. You will be able to see where you need to trim and the paint can won't buckle if you have to manipulate it a bit to get it through the hole. Once the feed tube is in, push it so it's half way out of the paint can. Illus 6. Now fit the stack onto the feed tube and place it just inside the edge of the hole. Illus 7 When your done, position the cans so the stack is in the center of the paint can.
Illustration 6: Fitting the feed can
Illustration 8: Center the stack before filling
Step 5: Fill the paint can with sand, dirt, gravel, or any material that will help insulate the stack from the paint can and stabilize the feed tube and stack. Insert the feed/draft tube plate.
Illustration 9: cut the feed/draft plate from a third can making sure it will fit about a third of the way up the can.
Step 6: Lets get burning! I placed small sticks in through the stack on top of a cotton ball, lit it and then filled the feed tube. Once the draft gets going there is virtually no smoke and if you keep feeding it, you'll be cooking or have boiling water in no time.
The grate I used on top was temporary from the grill. I have found that a small stove burner fits perfectly, or if you use a left over grill grate and cut it down it will fit inside the can and you will always have it with you.
Only using the Pea gravel as filler, the can was still cool to the touch after 20 minutes of burning.
Tip: You can regulate the heat output by blocking part of the air intake on the bottom of the feed tube.