Rocket stove query

I've seen many designs of rocket stoves online, I am curious is it possible to have the fuel chamber not fitted with a metal casing but instead use some sort of alternative thats non conductive? I mean the glass is cool but can the door be made easily out of something else? maybe cob,

Hi Rajesh, you can build a J-Tube rocket stove using no metal.
You would want clay bricks for the burner core, but the rest can be cob.

I built a rocket fired cob oven about ten years ago. It is an L-tube design, with firebricks for the lower half of the front half of the horizontal firebox to resist scraping of logs during loading. All the rest of the firebox and riser is cob. It gets intensive use one weekend a year and occasional use otherwise. The cob part is all still in fine shape.

Glenn Herbert wrote:I built a rocket fired cob oven about ten years ago.

That is a beautiful thing Glenn - Does the fire exhaust come out of the dragon's mouth? Brilliant!

The dragon's mouth is the exhaust, though fire never makes it that far. Flames seldom reach into the oven cavity. It smokes impressively at startup, or a bit when loading a big log.