Kent Hendy

So should I still aim for three/four parts grog to one part clay for the inner dome?

So I'm currently underway building my rocket powered pizza/cob oven and I managed to buy 80kg of calcined flint clay.
I thought I was buying flint or fire clay that I was going to use for my cob dome, but it turns out I didn't know what "calcined" meant.

For those of you who were like me, it means it has been super heated and turned into pottery and therefore won't react with water.
So I guess it's effectively grog or crushed fire brick.  It has the consistency of fine beach sand.

So now I'm thinking I will just use the clay I dug up from around my house, but should I use this "grog" as the sand in my cob.
Or should I do a mix of sand and grog.

Any thoughts?

Glenn that is an amazing rocket oven.
I'm inspired to try make a dragon like yours but I suspect I wouldn't quite have the cob skills to do it justice.

I think I will go J-tube and bring the heat riser into the center of the oven under a baffle plate.

Still haven't decided where to bring out the exhaust. What different characteristics do you get out of bringing out the highest point of the dome vs lower down toward the door?

Presumably with the latter you get a hotter/more effecient oven as the hottest air gets trapped at the top and you vent out cooler air but I wonder whether you get uneven cooking as the majority of air travels from the heat riser toward the exhaust.

Kind regards,
Kent

Hi everyone.

I'm in the process of designing a rocket pizza oven that /i will start building in the up coming months.
I've just got a few questions I wouldn't mind some expert opinions on.

Firstly Whether to do a J tube or L tube.  I know most people are building J tubes but I've heard that it is easier to control temperature with the L tube.
Considering it is for cooking I thought this might be ideal.

The second question is where to bring the heat riser into the oven.
There aren't too many videos but I have seen two main designs.
- Bringing the heat riser up in the very rear or the oven and venting the chimney out the front near the door, the cooking surface would be on the brick oven floor.  This would bring the hot air up over the cooking food (pizza and pies mostly)
- The second option I have seen is bringing the heat riser up through the center of the floor, suspending a cooking surface like a pizza stone and then venting the chimney out of the top/center of the dome for even air flow around the food.

Looking forward to hearing your ideas.

Kent