I love the idea of a wood fired oven, but I don't like the idea of building a massive mason structure and I don't like the idea of burning tons of wood to get the oven up to temperature (see DennisHartley50 video on the tube). But I don't want a sealed oven that just happens to be heated by wood -- I want the food cooked directly by the wood (the heat/smoke will make contact with the food). So I'm thinking dennis hartley's basic design (a rocket stove under and heating a 55 gallon drum) is a sound one, but instead of putting a sealed 30 gallon barrel inside the 55, I would place a mason/stone heating surface directly in the 55 gal drum, feed the rocket stove into the bottom of the drum, and let the heat/smoke run underneath and then around the cooking surface and exhaust the gasses on the top. I will, of course, like Mr. Hartley, place some kind of insulation inside/outside the top of the stove, too, to hold the heat in. Probably fire brick lining the top of the barrel and, if necessary, some sort of insulation on the outside. I think a huge advantage of the rocket stove in this application isn't just the economical use of wood, but the fact that the more efficient combustion means more heat on the food and less smoke (than the typical wood oven in which you build the fire right next to the food).

Clear so far?

But here's my question. I'm trying to figure out the best placement of the stove under the barrel (front, back, middle), the best place for the internal venting (should the heat/smoke run around the cooking surface up front, in back, all up and down the sides, etc.), and where should I place the chimney (front, back, middle).

I have drawn some crude plans. In A, the cooking surface runs from side to side the length of the stove, except the gasses either vent in the back or the front, or even in a hole in the middle of the cooking surface. And I have to decide where the chimney vents for each of those senarios. In B, the cooking surface is narrower so that it the heat can vent all down the sides and/or in the front or back or both.

Anyway -- I'd be grateful for your suggestions. This is my first rocket stove experiment. I'm hoping to build up my courage to building a bigger rocket heater in my barn/shed.

Pablo : Google Aprovecho baking oven or Aprovecho bread oven, complete with plans it is can adaptation of their industrial/commercial cooker and exactly what you want !
Via con dios! For the Craft, think like Fire, flow like a Gas, Don't be the Marshmallow !Comments and questions are solicited, and are Welcome ! PYRO - Logically Big AL !

P.S. you are putting the cart before the horse, the oven is harder than the whole Rocket Burner/Thermal Mass bench ! G'luck A. L.

The Winiarski stove is vertical, whereas the Hartley stove is horizontal. But both stoves seal the food from the flue gasses, which isn't the way a wood fired oven is supposed to work. I suppose I could figure out some way to eliminate the outer barrels in the Winiarski stove so the gas/heat can go straight to the bread using the same three shelf vertical method, but I'm not sure that gives me any big advantage and it might mean the bottom shelf burns the bread and to top shelf.

Maybe the Hartley design is in book II?

AH! Found the pizza oven version! But it, too, seems to be a two barrel design.

Well, anyone who has vent/rocket placement advice, I'd be much obliged.

Pablo : You are putting the cart before the horse, this project -Especially the way you want to modify it is much harder than a rocket mass heater build !
However, lets take a look at what you need, and go from there !

Google Aprovecho Rocket Bread Oven, this should take you to a You tube video. Complete with plans, hundreds of these have now been made, they are
a modification of Aprovecho's institutional/commercial models, of which thousands have been made, it is the simplest build, and is closest to your needs !
Via Con Dios! For the Good of the Craft !

Think like Fire, Flow like a Gas, Don't be the Marshmallow !As always,your comments / questions, are solicited and Welcome ! PYRO - Logically BIG AL !

Pablo : Srry,I got an error messge and re-typed and resent my answer you certainy can always put in a wood chip smoker box, that will give you enhanced
flavors, but without the thermal mass/ just letting the flow of wood smoke flow thru your single wall oven will drastically raise your "fuel Bill' and not concentrate
the heat enuf ! I understand what you want, you are fighting against the laws of physics ! G'luck, Vio con Deos ! For the Craft ! Big AL !

Pablo, Welcome!

Here's a video of a guy who has built something that's almost exactly like what you've drawn...



This video shows some of the limitations of his design



I understand that you want to be able to incorporate the actual smoke from the wood into the baking chamber, so as to impart flavor, but I think the purpose of the "two-barrel" design is to allow for the use of scrap or less desirable wood as fuel, thereby protecting the food from any foul aromas. However, with the "two-barrel" design, you could simply place a few small chips of whatever wood you like in the bottom of the baking chamber (have you tried pecan shells? --fantastic!)

Thank you for the welcome.

Yes... I saw this design -- I'm going to steal a few ideas, but I'm going to try the open burn method first.

Actually, I just found an old commercial/stainless wall oven on clist for a few cents and I might try that as an experiment. Try and drill a hole on the bottom for the rocket and one on the top for the vent. Already has pretty good insulation and a nice heavy door. Put a few stones in the bottom for mass and then see how it cooks. If everyone loves it, then I can move my rocket to a barrel or go all out and design a rocket powered adobe/mason pizza bread oven.

I'll keep you posted. I bought portland cement and perlite tonite. Going to cast a 5 gallon rocket tomorrow and maybe have me some wood fired bread for Thanksgiving!

Pablo : Portland cement will not take the heat and will fail above 600F, possibly explosively ! BIG AL

Why don't you try this... Build small rocket stove in a metal 5gallon bucket... With heat riser protruding a inch or so above the bucket rim. Take 30 gal drum cut it down so that it is short cut hole in bottom to fit heat riser into. Use bolts the create a stand for a pizza stone inside about 2 in above heat riser put door in drum and a vent stack on top... Should do what you are wanting

Pablo, sounds like you are on the right track.
I have seen a few designs powered by bucket rockets that worked very well.
Please share your experiences repurposing the conventional oven, this is an idea I have been wanting to pursue myself.

http://www.youtube.com/watch?v=5OIZekftbxw

This is a two part video

Brian -- Right where I was headed, but the caution against Portland has me heading back to Homedepot for an alternative.

William -- the guy with the oven said he'd already scrapped it. Sigh.

Home Depot probably doesn't have the type of material which you need. High temperatures require pre-mixed fireclay. Find a supplier of refractory materials in your geographical area.

http://www.backyardmetalcasting.com/refractories.html

this is a normal refractory mixed used by alot of diy foundry's their goal it to hit temps as high as possible to melt metal as fast as possible...

whats good for the goose is good for the gander..lol very similar to the info you'll find on diy refractory around here..

You're right -- nothing at the depot, but you link was helpful, Brian. I will look for a mason supply place tomorrow. Was hoping to have woodfired something by Thanksgiving, but I'm cutting it pretty close. Maybe Christmas.

Any confirmation on this mix for a high temp concrete? The video claims that masonry mortar mix is typically rated to 2500 degrees. He mixes 50/50 masonry mortar mix and perilite.

http://www.youtube.com/watch?v=ZZAoohv4ku8

Pablo S. : Mortar mix is simply a good grade of clay(the glue) mixed with sand , Mr. Bacon and I only Quibble over whether it can be called Concrete at all !
Mortar mix and Perlite will make a heavier and less insulating, but quite strong finished product. clay (the glue ) and the sand and Perlite( the aggregate )

A good grade of Bagged clay labeled ether fire clay ~60~ from a ceramics wholesaler or labeled as mortar clay at a building supply place, will when mixed
with sand, form a much lighter weight more insulative composite material though not as strong !

If you had firm plans, determining the best mix i e strength or insulation would be easy!

The clay with Perlite only should be capable of being placed in a form, fired to dry in your kitchen oven and if it is not sturdy enough for your job it can be
softened with water and recast with the addition of masonry grade sand, This material will not set or cure like Concrete, Basically You are making an adobe.

The finished project must have a finish waterproofing coating added if it is intended to be used out-of-doors>

For a good link to more information on clay and bricks goto>' traditionaloven.com/articles/101 ' dig around there are over 100 articles, much dealing with your
issues ! For The Good of All things Permies BIG AL !