Ever heard of a rocket stove? Neither had I. But see, that’s the beauty of sharing my life with a soldier, who also happens to be a Prepper. A Pragmatic Prepper, of course, in case of natural disaster. We do live in Canada and we have been known on occasion to get some pretty crazy winter storms. He’s not a crazy zombie apocalypse prepper. Not really, anyway.
He introduced me to the idea of a rocket stove a couple of months ago. It’s a small cooking stove made with very basic materials and physics. It needs a chimney, an air draw, and simple fuel. That’s it. Rocket stoves can be made out of a variety of materials (bricks, metal cans, or sheet metal) in a variety of ways but the premise is the same. Simple fuel (usually sticks) burns hot with good airflow, the heat goes up the chimney that has a relatively small diameter and it creates heat to cook. It was designed as a rudimentary way of cooking in areas of the world where electricity or space was an issue (ex. in refugee camps).
I was game. It’s always a good idea to have a backup way of cooking, in case we run out of propane and we don’t want to have to light the cookstove in summer. And the idea of having a very simple stove that would always work was very appealing to me. While I would not describe myself as a Prepper – I’m way too optimistic about life – I have spent enough time outdoors in remote areas to know that anything can happen and it’s a good thing to be prepared to provide the essentials of survival at any time, in any condition.
The materials that Soldier Boy bought were very inexpensive and could be found at any hardware store: patio stones from Home Depot for less than a dollar each and a foot of chicken wire from Home Hardware for just over a dollar. Not bad.
There is a certain pattern in which to construct the rocket stove when building it with bricks and the first two layers require a half brick. We didn’t have the tools to break a patio stone in two but the ever-industrious one-legged soldier found two half bricks under the wood shed. (Me: “From under the shed? Really? Like, supporting it?” Soldier Boy: “It won’t fall over”.) We put a gas stovetop element on the top to rest the pot or pan on. We took it off of the old propane stove that was in the cabin (and not connected to any propane). Here’s a video of how the stove is put together.
Building on a 12″x12″ patio stone, we used 19 full bricks and 2 half bricks. You can create a higher chimney as well just by continue to layer bricks. This not only allows you to add more fuel, creating a hotter temperature, but the greater the thermal and pressure difference (between outside and inside the chimney) and the higher the chimney, the better the draw up the chimney of the hot air. (Yes, I looked up chimney physics and it’s surprisingly simple.)
So does it work? I had my doubts. It doesn’t look like much of a stove and I wasn’t sure how hot it could get with just tinder as fuel. But watch this…
(Please ignore all the junk in the background.)
Yep. Soldier Boy did it. Now we have an alternative way of cooking and heating.
We used it again this past weekend to boil lake water for dishes. He added in a small screen to try to curb the amount of ash that came up through the chimney but this actually worked against him. Because of the screen, fuel couldn’t be fed in the top, it could only be fed through the bottom and so the flame never really grew. Putting more biomass in the chimney allows the flames to grow bigger and hotter as it burns more fuel. Also, using only small tinder doesn’t create a great amount of heat either. Perhaps if you only need to heat something, it would be sufficient but trying to boil a huge kettle of water was not going to happen. Taking away the screen and adding more and thicker pieces of tinder or short pieces of kindling brought the water to a boil much faster (relatively speaking). As it was, it took almost an hour to boil 4L of water.
An hour?? This sounds like a looooooong time to be sitting in front of a stove, doesn’t it? Yes. But in winter, it won’t be fun to snowshoe 3 km with a full tank of propane, even if it is on a sled. So conserving fuel is a good thing. Even in summer, conserving propane is a good idea. Just last week, I was in the process of boiling water for coffee and the propane ran out. So, instead of facing the world caffeine-less (we all know how THAT’S going to end), I fired up the rocket stove with just enough water for a cup of joe.
One last point worthy of mention is how black the pots and pans get when used over the open flame. We all know what it looks like after putting something over a campfire and this is no different. We boiled a large pot for corn over the rocket stove one night and the bottom half of the pot was black. It washes off with some good old-fashioned elbow grease but we decided that we’re just going to bring out some of our oldest cooking gear and it will be designated for the rocket stove.
Cost of Materials:
- 20 paver stones, $1 each (Home Depot): $20
- 12″ x 12″ patio stone (Home Depot): $2.29
- 1 foot of chicken wire (Home Hardware): $1.40
- stovetop element: free with the cabin
Total cost: $23.69