Rocket pot oven

[PsychDoc]

I began construction. A series of experiments led me to this. The simple idea is a rocket stove heating a clay pot with a 13" pizza stone inside. That sounds easy right? If this works I might use a larger pot as the dome for a WFO. If that doesn't work I will continue with the brick dome plan.
I shall attempt to post pictures as I progress.
Notice the fancy brick work.

[Hendrikwal]

Re: Rocket pot oven

Hi there, im playing with the same idea, how did u go and what temp u get with a small rocket stove?

[PsychDoc]

Re: Rocket pot oven

Okay here is the update. I'm using 6" tube for the rocket stove portion. Upsized from 4" coffee cans.
The pot and saucer combo is 16" from Mexico via Home Depot. I started cutting it with abrasives on the angle grinder but sprung for a diamond blade on my last trip.
What else? I hope to do a lot of work this weekend, I can barely squeeze in one course of brick on a work day.

[PsychDoc]

Re: Rocket pot oven

Is there a reason I can only post one pic?
Here is the pot

[Hendrikwal]

Re: Rocket pot oven

He there, looks like a nice big pot that wild hold pizza, i might want to use thicker metal pipe fpr t rocket stove, i have used a few stoves. And i started out using think metal like u but if u use for some time they wil get so hot. That the metal wil disintegrate over time.
It wil last for a month. Of daily firing. I used cofeee cans first time, and same pipe as u have 2 nd time and for my pizza oven i wil use proper steel pipe since i wil put it under the base of my oven and cant make repairs, i. Wil make a smaller oven so i hope to get good temp with a big rocket underneat t oven.
Good luck. With project, let us know. How it works

[PsychDoc]

Re: Rocket pot oven

I just thought I'd throw up today's progress. I put down a couple of courses of bricks. And use my diamond cutter to make a door in my pot. I've learned that brickwork is much harder than it looks. And that a tiny bit of water your mortar makes a huge difference. I believe the lego company lied to me as a child.

[Gulf]

Re: Rocket pot oven

I am following this with great interest! Not for the rocket stove angle, but for the terra-cotta pot as a form for a simi-conventional pompeii. Maybe a 4" natural clay or fireclay and type N mortar (50% hydrated lime and portland) shell used for thermal mass. Maybe just clay or firebrick layed against the terra-cotta form, should it fail. Maybe even combining a paired set of the cheaper unglazed terra-cotta pot and a small chiminea as a form.
Just sayin"

[PsychDoc]

Re: Rocket pot oven

A couple of answers, and a question or two.

Hendrik, I most have glossed over your first question, sorry. It looks like you wanted to know about early testing. So, here goes. I made a small rocket stove with soup cans- around 3" diameter. Chimney about 12" tall. I surrounded this with red brick- this was simply to hold a flower pot but may have provided some minor heat retention. Over the exhaust of the rocket I inverted a 12" pot that had been rotting in a small pond. (Nothing but the finest for me) the set an oven thermometer inside the pot. Within a few minutes I was at 5-600F. The tiny rocket stove, and my distractibility, didn't necessarily provide scientifically verifiable results.
Gulf, you may be interested in another trial I did. With a small pot set up as described above I had a temp around 400F. I wondered what might happen if I place a second larger pot over it for insulation. The temp shot up to 600+. You described various layers in your post. I thought about the same thing as a way to save time and maybe a few $$$. I think an insulating layer might be needed but takes away from the look.
Hendrik- do you think the wet weather contributed to your pipe decomposition?
Also I have seen "black clay" pots that are made in Vietnam. They are supposed to be high quality and fired at a high temp. You may have access to that type of pot. That might be a good dome, they are expensive around here.

[deejayoh]

Re: Rocket pot oven

Is the heat is only coming from the bottom of the oven in this design? It is going to be tough to cook the top of a pizza before the crust burns.

[PsychDoc]

Re: Rocket pot oven

Good question. The answer is yes and no, in theory. Yes the heat is all generated below the oven, however there is space around the entire "floor" that allows the hot rocket exhaust to enter the dome and then be reflected back to the top of the pizza. At least that's the theory.

[Wiley]

Re: Rocket pot oven

Am I missing something? Looks like you cut the bottom out of the pot...The 63 % height of door to interior of dome was for airflow within the "dome" with a fire within the dome. The exhaust fumes need to flow out the 63% opening and either into a chimney or to the wild blue.

But interesting thread, I like to see people thinking outside the box.

Bests,
Wiley

[PsychDoc]

Re: Rocket pot oven

Wiley, pardon my sarcasm, but the other reason for the door is access to the pizza! I will have a hole in the 'top' of the pot/dome for venting during fire up. Then I can cover the hole to retain heat.
Much of this is proof of concept and will likely be modified in "rocket pot mk2".

In other news I found a pottery shop that has 24" bowl shaped pots, 9-10" deep or so for $31! That may serve as a dome/form for future oven. Maybe over a soldier ring of bricks...?

[shuboyje]

Re: Rocket pot oven

I would personally leave the pots behind and get a kiln shelf. With bottom heat only ovens like you are attempting to build the top heat is always anemic compared to the bottom. To have any chance of balancing the heat you will need as low of a "dome" as possible. A kiln shelf set on top of a low brick wall would give much better results.

[Hendrikwal]

Re: Rocket pot oven

Mighty intersesting results, i had no idea u could get that kind of heat from small rocket inside small oven like that. We have a lot of verry cheap terra cotta pots around here, i never seen t black ones, altough i know wich ones u mean, but the best of t best is for export in this country and local population is so poor they cant aford those i think, but i bought 5 big flower pots with 40 cm diameter for 5 dollar, so i can aford to screw things up and brake a few pots experimenting haha.
We also have a lot of bamboo. Wich makes great rocket stove fuel but crappy pizza oven fuel as it burns away like paper soaked in petrol.
Once i start building i wil post some fotos, at the moment they are building my foundation of my new house so i busy with that

[PsychDoc]

Re: Rocket pot oven

Thank you all for the input.
Hendrik - cheap is good, well sometimes. While the "black clay" looked interesting dirt is still dirt. Cob has been used with great success for many years so its nice that someone has dug it up and formed it into a pot for you. The pot I am using is 16", a shade over 40cm. Still only $8.
Shuboyje- low dome is defiantly the way to go. If a person is trying to use a single pot they need to balance sufficient side wall to allow a door for access and low dome hight to help reflect heat. And while I appreciate the input, your comments here and on another thread come across as absolute and somewhat patronizing. I'm sure your experience with authentic Neapolitan pizza and the associated ovens is great, I'm trying to have a little fun with an alternative method to cook a decent pie and maybe a bread stick. I have under $100 in this thing and its only that much because I didn't want to bother with the time to source materials. Not everyone has the time, space, talent, or treasure to construct authentic.
Now then... Heat on top, while I'm hoping the dome and design work as is, I may suspend a terra cotta tile above the pizza stone to reflect and radiate heat to the top of the pizza. Ia am using a tile under the stone as well as diffusers to avoid over heating the bottom.
Hopefully I will be able to get some more done today and post a pic.
Roger