A Redneck Rocket Stove

From Wes Duncan, the “High Tech Redneck,” a rocket stove made out of cinder blocks. I’ve built one of these too and can confirm that they work great. And you can’t beat the price. Time for some redneck cookin’!

Update: As several readers have pointed out, this design ain’t safe. Cinder blocks can explode and were not meant to be placed next to a heat source–that’s what fire bricks are for. See our post about our backyard rocket stove for a safe design that uses metal pipe.

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13 Comments

  1. Wonder how well this might work, if there was a chimney added, to put any significant heat into the interior of a tiny house?

  2. I’ve researched rocket stoves before because I want to do my canning outside this summer, as it heats the house way too much. I’d envisioned some lovely tiled thing that looks much like an old Mexican kitchen, to go with the earth oven I’d like to build out there.

    This is a GREAT alternative if I can’t get my low-tech outdoor kitchen built in time for canning season. Which I probably won’t, so thanks for this- I think this is the lowest tech I’ve seen so far, and super easy and fast to get accomplished.

  3. I love this site, Homegrown team. It’s a glimpse of a shiny happy future.
    But…
    Fire brick, people. Wiki ‘fire brick’. When some things get very hot, and then you spill cold liquid on it, the material can crack or explode. Fire brick won’t do this; it’s used to line your fireplace, for example. Or use lava rock cut into slabs.

  4. This is great and I’m enthusiastic about the creativity. A few thoughts:

    If he had placed the pan direction on the block instead of on a grill, he would have had more heat transfer, resulting in more rapid temperature gain and higher top-end heat. Since the block is square and his pan is round, so long as there remains a 1″ gap in each corner for the exhaust, then he’ll have enough flow to maintain combustion.

    Cinder-block is not intended for high heat. This rig is a little risky if high heat is maintained long enough to heat the block in its entirety. As a previous commenter said, cinder-block is prone to violent disintegration when there are rapid changes in temperature. Cracking is likely, losing your meal. Shrapnel is a possibility.

    Consider loosely mounding dense soil around this setup for protection from the “oops” factors and to further increase thermal flow through the chimney and to your meal.

    I still think it’s cool…

  5. Thank you readers. We were considering putting this in our book, but you are all correct that this is why god gave us fire brick. Would not want to be responsible for cinder block explosions across the US! Will stick with the perfectly safe rocket stove design in our first book–click on the “rocket stove” label above to see some other, better designs.

  6. I recently built one of my own to try. Yes, the block WILL crack if there are “thin” spots (as in the seam in a Sash block) – but overall the design seems to be robust for something made out of easily obtainable materials. The composition of the block provides a fair amount of insulation. I did make some minor changes to the design to make it work better with small twigs.

    I have tried other “Rocket Stove” designs – this is far and away the most “cheap and dirty” design I’ve seen for a stove to use under emergency conditions. Other designs work as well or better, but require much more effort to construct, as well as more tools and talent. In an emergency, you can make one of these with 3 blocks and a hammer. As an emergency stove, to be used for a limited time, I give it a 8/10. As something for long-term use, more like a 4/10.

  7. The cinder block does crack. No violent explosions here, just done muffled popping sound then cracks appeared on any blocks exposed to direct heat.

  8. well your statement about concrete and heat another forum some persons brought that up too, he did much more research and it is not a concern from a rocket stove amount of heat. only an issue if like heat from a plasma cutter was applied, which twigs would never produce that are used in a rocket stove. then i bet you could apply high heat paint to the chambers helping it also.

  9. Pingback: Is it safe to use cinder blocks or red bricks in stoves and ovens? | Root Simple

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