I like rocket stoves, these are usually small, usually portable, mini-cooking-heating devices that are very efficient. You can use twigs instead of larger pieces of wood, these tend to be safer since you aren’t using a lot of fuel (twigs) and it goes out if you aren’t there to feed the wood into the stove. I have seen a lot of different methods of building a rocket stove, from simple bricks without mortar to very elaborate and expensive rigs.
I recently ran across an interesting and easy to do method of making a rocket stove from materials that most of us have laying around the house. This was designed and created by an internet friend, Kent Ivey, who is a major tinkerer, he is always coming up with interesting and useful items made with scrap or what most would consider junk, those of us who follow him on Face Book are always eager to see what he comes up with next.
Here is a photo montage of Kent making a rocket stove, enjoy!
You’ll need a 5 gallon bucket (make it one you are willing to give up for this purpose)
2-2 liter plastic cola bottles (full of cola or water)
A marker that will mark on plastic
Dirt, straw or hay or grass, water
A sharp utility knife, duct tape, something to mix the cob in and scoop the cob into the bucket (wheelbarrow and shovel)
Something to smooth the adobe/cob (a trowel of some sort)
A piece of expanded metal lath, or something similar, that will fit in the middle of the lower hole and stick out at least 6 inches, longer would be better (make sure it can take heat)
Rocks or something to set your pan on the top, you’ll need a space between the top of the rocket stove and the pan
After you get all of your parts together, set the bucket on its side, draw a circle on your bucket toward the bottom, about 3-4 inches from the bottom, use the cola bottle as a template.
Next, using a sharp utility knife, cut out the circle, be careful.
Make sure the bottle fits, it’s OK for the hole to be a little bigger than the bottle.
Now using duct tape, tape the two bottles together in an “L” shape as shown. Tape them well, be sure to cover every part of the bottles between the bottles, make it as smooth as possible.
Now make your adobe/cob using the dirt, grass (or hay or straw) and water, if you are unfamiliar with making adobe/cob, just look it up online, there are lots of resources to teach you how to make adobe/cob.
Put some of the adobe/cob in the bottom of the bucket, just until it reaches the bottom of the bottom hole, place the taped bottles in the bucket, then continue filling the bucket with the adobe/cob mixture.
Make sure the “boss” is watching.
Be sure to fill all of the voids, do not leave any holes or voids in the bucket.
Yeah, it’s messy, you’d better do this outside. :)
Using a trowel, smooth off the top of the adobe/cob, Kent piled the cob up a couple of inches over the top, he smoothed the top and the sides.
Clean up any adobe/cob that oozes out the hole in the side.
Now allow this several days to dry, if you live in a very humid area, leave it a few days longer.
When the adobe/cob feels dry, open the bottle lids and pour out the liquid.
Using a sharp utility knife, cut the bottle tops and remove.
Carefully reach in and cut the sides of the bottles, remove the bottles and tape as best you can.
Chances are, your adobe/cob will not be completely dry inside, allow it to dry for a few more days.
Using some small twigs and paper, set a small fire inside the rocket stove to help dry it the rest of the way and start to cure the adobe/cob.
Now take a piece of expanded metal lath, or something similar that will fit in the bottom hole, this is used to hold the fuel as it’s being fed into the rocket stove. Notice the rocks on top, Kent uses this to hold up the cooking pan, you can use whatever heat proof item you have to set the pan on.
Now, stuff some paper inside the bottom hole, place some twigs or other wood on the top of the screen, light it and wait for the fire to catch.
Once the fire is going good, you can cook on your rocket stove, you can also boil water.
Notice how the pan is not sitting directly on the top of the rocket stove, there needs to be a gap between the pan and the stove. Keep pushing the twigs into the stove to keep the fire going.
Looks like Kent had a great breakfast right after this. :) I think the boss got some breakfast too.
I know someone will ask this question, will the plastic bucket melt? According to Kent, it will not melt.
20 Responses
This is to be used outside and not for heating a room. This is for cooking. We did a report on this site a while back on a rocket stove for heating.
So I built a rocket stove to heat our green house our second winter here at endless enigma farm, and I have to tell you it was a waste of time, for the punt of time that I spent feeding wood to the stove verses the amount of heat it gave in my opinion it was a waste of time. My little thirty gallon air tight barrel stove does great. I can load it and forget it for five hours and usually has enough coals in it so all I have to do is reload it again and I’m done.
I like this design for the economy and simplicity of the materials! Using a dense material like cob does sacrifice some efficiency, as the material absorbs heat, thus making it unavailable to the cook pot. The trade off is that the absorbed heat will be stored in the cob and slowly released, acting like a mass heater.
I think that mixing something like perlite or vermiculite into the cob would increase its insulating properties (if you were interested in getting maximum cooking bang for your buck with your fuel).
Also, the fuel feed platform should ideally have some space beneath it. This allows for air to get in underneath the fuel, for a much more efficient burn.
I learned all this by reading “Design Principles for Wood Burning Cook Stoves”, by the Aprovecho Research Center. It’s easy to find online, and has a great chapter on the design principles of a well built stove.
Again, compliments on your design, and happy hacking!
Dave
Would like to build a stove to use for heating basement in Ky. Still have cooking uses when heating. Thank You. Leo
I have the idea of allowing the adobe to dry around a few long pieces of steel (grating for the top) to be used to sit all of the pans on. I will be building something similar to this soon and will probably either photograph it, or video it. Thanks for the idea!
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I was wondering if you could use concrete instead of adobe/cob, heard that concrete can explode under high heat.
Badger,
Hmmmm, I don’t know about that one way or the other, there is a refractory cement made for high temps, if I were to guess about this, I would use cob or refractory cement on the burn chamber and regular concrete on the rest of it… I even thought about using cob but adding a small percentage of cement powder with it for strength, but I’d test it first to make sure it would work before building the whole thing.
Wretha
Could you somehow incorporate an oven into
this stove?
B J Fisher, check on YouTube, there are lots of videos and tutorials about this, I’m sure there is at least one that would be able to help you.
Wretha
Good sound idea. We used to make essentially the same thing fifty years ago out of stove pipe of various sizes with a reducing T and an elbow for the stack. Worked wonderful.
I would like a chiminea in my yard were on a fixed income This is what we need. Please send me all instructions, Thanks Rosalie mondacci
Hi Rosalie, I don’t have any written instructions, just the pictures.
Wretha
Very cool, thanks for the pictures! Here in Hawaii we build Chiminea’s out of lava rock. They work pretty well, only trouble is finding wood dry enough to burn l0l :)
I like this one a lot, been wanting to try one. I have been mixing clay plaster in plastic buckets today, tempted to take time to make one tomorrow!
Matt
That’s great Matt, let us know how it turns out. :)
Wretha
Hi Wretha,
Listen, no need to wait on that oven. You could build one cheap. Go to a welding shop or weld it yourself. Take 3 pieces of mild steel, say 5 feet long. Weld them together into a capital H shape. Repeat the process 3 times. Weld them into a open box, like a capital C, closed on 3 sides, open on one.
Place crossbars, like a capital X, on the bottom, the middle and the top, and use that grid steel you used for your stove as the platform to burn wood upon, use that same grid steel to create 3 flat surfaces at the top of the H, the middle and to bottom and you have your oven’s skeleton.
Now start piling that same adobe earth mix to fill out the skeleton, to make an oven. Wrap with chicken wire to hold the earth in place as it cures.
Light a fire and keep it burning on a low heat for 2 or 3 days, to cure the adobe. Presto, a pizza oven = )
What do you think?
A.
Thanks Alex, it’s just one of those projects that is low on the list of important things to do, yes I would love to have one, I already have a plan in mind for how I will make one when the time comes, it will probably be in a dome shape instead of square, but that’s just me thinking. :) I love making homemade pizza and homemade bread, it will be fun learning how to bake in an oven like that.
You sound like a real go getter, my hubby is that way, he thinks of something and he goes out and figures out how to do it with the materials on hand and he does it.
Wretha
I like this idea. The only thing I think I would change is that instead of using the coke bottles I would try to find some heater duct pipe and use it instead and just leave it in the opening.
This is a very nice stove, and useful if you plan to move around, as well as being very efficient burners. However, if planning to stay put in one location, I suggest a larger clay oven, like a pizza oven, which will take longer to construct, but not cost that much.
I lived with an oven like that when I was a kid, and they’re great. Light a fire in the morning, they stay hot all day long, and warm most of the night. You can cook a roast or turkey in the back of the oven, bread & pizza in the middle, at the same time as you’re cooking vegetable casseroles on one side, heating coffee on the other side, etc…
Yeah, nice one, thanks!
Thanks Louise,
Alex, I want an outdoor pizza/bread oven, maybe…someday… :)
BadVooDooDaddy, that sounds good, just make sure it’s not anything that is galvanized, they put off toxic fumes when burned.
Wretha