Introduction: 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:
Step 1: Materials and Tools
- 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
- 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:
We have a be nice policy.
Please be positive and constructive.
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.
I read somewhere that rocket stoves need a chimney that 3 times the length of the firebox to draft effectively, and accomplish gasification.
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
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.
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.
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.