How to Make a Rocket Stove

In this Instructable I make a rocket stove that can be used to cook on.

I wanted a stove for emergencies that wasn't reliant on compressed gas or alcohol and while those fuels are very easy and reliable, if you run out and you can't buy more you are stuck. Its fuel source is wood, which is of course usually very easy to get.

*Originally I built this stove for a DIY pizza oven so I could cook pizza's quickly but it can be used to heat a pot on as well. That Instructable can be viewed here:

https://www.instructables.com/id/Beer-Keg-Pizza-Oven/

Step 1: Materials and Tools

Materials:

• 4" x 1/8" Square Pipe (Inner Diameter)
• 3 3/4" x 1/8" mild steel stock
• Steel Rod
• Bolt and Nut
• Small hinge
• High heat paint

Tools:

• Welder
• Angle grinderwith cut off disc
• Wire brush

Step 2: 1st Design and Testing

So this was my initial design of the rocket stove, I'm including it so you can see how I change the design until I ended up with a final design.

I started with the square tube and marked it at a 45 degree angle cut it in half. On one piece of the pipe I welded in the steel plate inside about 3/4 of the way from the top of the pipe (see the pictures or video). This piece of steel will be the fuel shelf of the stove. The bottom opening will be the air intake.

The two pieces of pipe were then matched up at the 45 degree cuts and welded together. The piece without the fuel shelf will be the chimney.

For testing the stove, I used some hard wood kindling and pushed them into the stove and ignited the ends of them. The way the stove works is once the fuel is lit, air is drawn in through the intake. This creates a stack effect which then continues to burn the fuel. The wood does need to be constantly pushed into the stove so it keeps burning. The stove does burn quite clean and efficient. However I did find that it wasn't hot enough.

The stove is technically finished but after testing I changed the design a bit to see if I could get a hotter stove.

Step 3: Design Modification

Because the ends of the wood are what gets burned, there isn't enough fuel to create a big amount of heat. While the stove does burn efficiently it doesn't burn hot enough for me.

To increase the amount of fuel that could be burned at one time, I decided to add a door to feed fuel into the stove from the chimney. Longer pieces of wood could then be in the stove and burnt at the same time. I also closed off the fuel shelf as the opening was too large to create a good stack effect.

I cut out a door and put it on a hinge and added a handle and latch. Longer pieces of wood could easily feed into the stove.

A mounted was added so the oven could be bolted to pizza oven project.

Some feet were made by welding on some bar stock on the bottom of the stove. A pot rest was made by welding on some 1" bar stock at the top of the chimney.

Step 4: Testing

Wood was added to the stove and then ignited. After about 5 minutes of burning, it got up to cooking temperature.

The stove gets to a higher heat with this design by feeding longer pieces of wood into the stove. I was able to boil a pot of water with no problems, although the bottom did turn black from soot. The efficiency could probably be improved by making the intake a bit larger or variable with a sliding plate.

I think with a few more tweaks this stove could work even better but for now it performs well enough.

This was the intended purpose of this stove:

https://www.instructables.com/id/Beer-Keg-Pizza-Ov...

Comments

[tytower]

This is whacky . Its not a rocket stove its just a wood burner . Same
as a pot belly . Pretty silly really because it does nothing for air
flow or wood feeding .

You have even closed off the feed chute and hand feed it from the front?

[stumitch]

Bear in mind that Instructables has a "be nice" policy. I think we can agree that this is not a rocket stove as such but please remember to be constructive in your comments.

[tytower]

If something is not what it claims to be ,or ,is not correct ,or, makes false claims , I will expose it as such , be nice policy or not.

[MalteLarsen]

"This is whacky" & "Pretty silly" ...? This is what he refers to... so please watch your words and keep your anger with you.

[tytower]

That is exactly what it is.

And you are ?

What is my comment to you?

[JayGee59]

If the stove isn't getting hot enough for what you think the pan
contents should be doing - step back and look at how high the pan is
above the flame! That could be part of your problem.

[craftyv]

This is a totally dangerous thing. Surging fire on a wooden deck next to a wooden building with dry grasses etc next to it. What could possibly go wrong? Oh yes a child or dog running into it.

[kkreitman]

I read somewhere that rocket stoves need a chimney that 3 times the length of the firebox to draft effectively, and accomplish gasification.

[AlanA134]

Do rocket stove need some kind of fire proof liner
to keep from melting and or distorting, thats really the only reason I haven’t made one.

[JasonL237]

I built a double rocket powered pizza oven. If you want more heat first switch to refractory materials. They won't absorb as much heat as the metal will, this will give more heat to the riser so the smoke can combust. Second, increase the diameter, larger systems burn hotter. I would suggest looking at http://donkey32.proboards.com/ website for some batch burn designs. In a batch burner you can load up wood and it will burn really hot. I managed to warp high temperature fire brick in my riser.

The one you built though is probably better at having different heat settings because you can control the fuel better. That is why I have two rockets, one fire for low baking and two for high. Good luck!

[jeff.ladd1970]

Looking at the shelf, is it possible that it is cutting the supply of oxygen? Perhaps holes in the shelf would allow more oxygen and a hotter burn?

[solarborg]

Not bad if you cut a 45 degree into burn chamber and feed wood there and use the old burn chamber ( horizontal ) as an air flow by drilling a series of holes in a 2" diameter circle in the middle and cut a 3" plate and bolt it on this will give you more control of the air flow. Feeding wood into the 45 degree is much better as gravity lets the wood slide down into the wood chamber. Also if you insulate the heat chamber it keeps the heat in and burns better.

Want to know more type in rocket stove in you tube there are loads on there.

[ArthurJ5]

Would a longer chimney make a cleaner burning sove? I made one from a Dixie cup dispenser as a Boy Scout and it would get red hot and roar with only sticks as fuel. Not surprisingly we called it a rocket stove. It would only smoke when starting and would run clean after that.

[jstork1]

I built a heating rocket stove for my garage (like a mass rocket stove without the mass bench) and when I was testing it outside, it would not burn very clean. Once I added more chimney, it increased the draft/air flow and it ran cleaner and better. I also insulated the back end of the combustion chamber and chimney riser which will heat up red hot and catalyze unburned smoke (provided there is enough air flow). Once it is hot, you can't even tell it is on when you look at the chimney.

[sue.donim.144]

i wonder if a divertor for pot to sit on would divert the soot . maybe angled a bit or ??? something that can pass the heat up but keep soot from pan

[signalsoldier]

Nice build and thanks for sharing

[calguard]

I like the concept, I have seen many different designs and am planing on building one. I will make the fuel feed chute angled so that when the fuel burns it will self feed, as long as air can get under the fuel it will remain hot. Here is one of my favorite designs that would fit in an ammo can https://www.ebay.com/itm/Shadrach-V2-Portable-Rock...

[PeterJ155]

Reminds me of the "cooker" my late father used as an army cook in WW2 in Iran. Same general shape, but scaled up about 10 fold. It had one continuous sheet of 1/4 in. steel about 6 ft long as the roof of a brick tunnel (the hot plate) with a 6 ft chimney at one end and a crude oil burner at the other. On a good day he claimed they could get flames out of the top of the chimney and burn through the 1/4 in steel in a couple of weeks.

[rondame]

you need to insulate the stack pipe so it gets hot enough to burn the wood gas which gives it its extra heat. just saying