temporary dry-stacked WFO - square design

[TylerDavis]

I am currently cooking pizza using upper and lower granite tiles on my propane grill. Works alright but I'm ready to take it to the next level. I have read the Pompeii oven instructions and have a spot picked out in my yard. However, before I take the plunge and invest all the time, labor, money and yard footprint for a permanent WFO, I would like the throw together a temporary dry-stacked oven for a season. I want to see how much we actually use it, with work, kids, hobbies, etc vying for our time.

I have seen this build
How to Build a Temporary Wood-fired Brick Pizza Oven with Cheap, Easy to Find Materials | DO IT: Projects, Plans and How-tos
but looking to go even simpler.

I have a built-in BBQ area with a decrepit charcoal grill that would provide the perfect base.

I'm thinking of buying a couple hundred refractory bricks (I can reuse them if I ever decide to build a full WFO)
Dry-stacking them with no mortar in a simple rectangular shape, 24"x24"x12" internal. I will hold it together with angle iron and threaded rod, and just try to be careful not to be too rough with cooking tools to knock it over. This is the same way I built a firepit using pavers and angle iron and that has held sturdy for 5 years now.

I will probably stack the bricks 2 deep, overlapping to minimize air gaps. Might put a short section of straight flue near the front. No door for now.
I realize that this design with minimal insulation and thermal mass will not heat as quickly and cool down faster than a built-in WFO. I'm OK with that, but it will give me some practice with cooking this way, to see if it will keep my interest in the long term.

Is there anything fundamentally flawed with a flat roof instead of a dome? I know the dome provides structural support but I am cheating by using angle iron instead of mortar and masonry techniques. I figure commercial deck ovens have flat roofs and they make good pizza.

Any other ways you could think to improve the basic design concept without adding a lot of labor and cost? I'm hoping I can get 700+ degrees cooking temperature with an afternoon of assembly. The 80% solution, if you will

[cobblerdave]

Re: temporary dry-stacked WFO - square design

Gudday
I've seen one of those ovens before. There are real eye opener and just go to prove that an ovens an oven that's an oven.
Tried to find a link to one in the other oven types section, but haven't found it yet.
Keep a post of your progress its should be an interesting build
Regards dave

[david s]

Re: temporary dry-stacked WFO - square design

Using concrete pavers under the firebrick floor is a mistake IMO. I think it would be difficult to get the floor temp up and to hold high temps. Floor insulation would be my first amendment. Then some insulation on the sides and the top.The steel bracing with angle iron and threaded rod is standard kiln building method.

[cobblerdave]

Re: temporary dry-stacked WFO - square design

Gudday
Found it and posted it to the top "Building the oven" by Tman in the other oven types section.
Makes a great read and if anything would give you a great amount of fun for a while , I'm a great recycler , so for my efforts I would put my time into something more permanent. But that's my opinion.
It's good that you considering using firebrick , they'll survive to be be useful.
Regards dave

[TylerDavis]

Re: temporary dry-stacked WFO - square design

Using concrete pavers under the firebrick floor is a mistake IMO. I think it would be difficult to get the floor temp up and to hold high temps. Floor insulation would be my first amendment. Then some insulation on the sides and the top.The steel bracing with angle iron and threaded rod is standard kiln building method.

I'm not planning on using any concrete pavers. The BBQ stand is slump block, then I will put a single sheet of Durock board, then a layer of insulating firebricks, then a layer of refractory bricks for the actual cooking floor. I'm hoping this will be a good compromise for floor insulation

Glad to hear the kiln-building enthusiasts have been down this road before. I presume they have a continuous propane flame source, but still like to insulate to keep costs down?

[TylerDavis]

Re: temporary dry-stacked WFO - square design

Gudday
Found it and posted it to the top "Building the oven" by Tman in the other oven types section.
Makes a great read and if anything would give you a great amount of fun for a while , I'm a great recycler , so for my efforts I would put my time into something more permanent. But that's my opinion.
It's good that you considering using firebrick , they'll survive to be be useful.
Regards dave

thanks for the lead
here's the link for myself and others:
http://www.fornobravo.com/forum/f43/...ven-14269.html

Sounds like TMan had quite a bit of success with his "temporary" oven. $50 and 4 hours invested. Little residual heat, but cranks out 88 pizzas in one session - hard to argue with that.

[cobblerdave]

Re: temporary dry-stacked WFO - square design

I'm not planning on using any concrete pavers. The BBQ stand is slump block, then I will put a single sheet of Durock board, then a layer of insulating firebricks, then a layer of refractory bricks for the actual cooking floor. I'm hoping this will be a good compromise for floor insulation

Glad to hear the kiln-building enthusiasts have been down this road before. I presume they have a continuous propane flame source, but still like to insulate to keep costs down?

Gudday Tylerdavis
Picked up your mention of propane flame. Sorry but its been policy on the forum for a number of years that discourages discussions on gas fired homebuilts.
Just common sense really , its just to dangerous. Leave the "gas fits"to the pros
Regards dave

[TylerDavis]

Re: temporary dry-stacked WFO - square design

got my bricks and dry-stacked them this weekend

fired a test-fire and realize I need some form of a door to retain heat. Can I screw a sheet of Kaowool blanket to the inside of a piece of plywood and use that as a door?

I had bought 1/4" 2300* felt blanket a few years ago but now I can only find 1/2" and it's gotten more expensive

[cobblerdave]

Re: temporary dry-stacked WFO - square design

Gudday
The prospect of bits of insulation of any type out in the open especially around food is not that appealing. Your better to seal it in.
If you can get hold of some airated cement block ( 1/4 the weight of cement) you can carve yourself a door to fit . Silastic the ply on the front and add a couple of handles. Links at the bottom for my door
Regards dave
Ps that link has Also has a pic of the worst most dog ugly door ever used.
Two pieces of ply covered with aluminium foil. Worked ....just. Survived more than three times. Couldn't stand it, so I made him one of airated concrete.

[TylerDavis]

Re: temporary dry-stacked WFO - square design

the aerated concrete looks intriguing; couldn't find any distributors in Arizona. Anyone in the states have a lead for me?

[TylerDavis]

Re: temporary dry-stacked WFO - square design

I've got my oven put together and fired it last night to cook some chicken thighs and root vegetables. Turned out fine; learned a lot in the process. The weak point right now is the door. I cobbled together a rectangular plywood back with fiberglass insulation shielded by aluminum sheet metal. It works OK for shielding the heat but doesn't fit tightly.

Can I build a perlite-concrete slab door to replace it? Is the perlcrete too crumbly for this purpose? I'm thinking of using the plywood as a form, then casting perlcrete two inches thick. Will the perlcrete withstand the direct fire temperature, or do I need to protect the inner face with something? 6:1 ratio of perlite:concrete? Then just enough water to hydrate it?

[TylerDavis]

Re: temporary dry-stacked WFO - square design

since I took these pictures, I have reconfigured the doorway slightly, and added ceramic blanket on the outside of the firebrick

[cobblerdave]

Re: temporary dry-stacked WFO - square design

Gudday
Good to hear you enjoying yourself with that oven.
Recon you could easily cast a pearlite cement door , and 6 to one sounds plenty strong. I expect it would be a lot like hebel , even though it has Portland cement in the mix you don't really need to place it on over 300C which is the point where Portland breaks down. Your main worry is dropping it it can shatter.
You really got dome cool pieces to play with firebrick insulated firebrick ceramic insulation. Recon if you should be done playing now and get serious on an oven.
Check out Budget build 36' in this section. I note the simplicity of the build no fancy cutting and the time line it was a really fast build.
Thanks for posting your results I'm alway interested in something different
Regards Dave

[TylerDavis]

Re: temporary dry-stacked WFO - square design

well I'd like to have the door in place during heat-up, which would be over 300 C. I plan to leave a hole and damper through the door to adjust airflow. Do I need to use refractory cement instead of Portland cement to make my perlcrete?

[stonecutter]

Re: temporary dry-stacked WFO - square design

I've got my oven put together and fired it last night to cook some chicken thighs and root vegetables. Turned out fine; learned a lot in the process. The weak point right now is the door. I cobbled together a rectangular plywood back with fiberglass insulation shielded by aluminum sheet metal. It works OK for shielding the heat but doesn't fit tightly.

Can I build a perlite-concrete slab door to replace it? Is the perlcrete too crumbly for this purpose? I'm thinking of using the plywood as a form, then casting perlcrete two inches thick. Will the perlcrete withstand the direct fire temperature, or do I need to protect the inner face with something? 6:1 ratio of perlite:concrete? Then just enough water to hydrate it?

Percrete is friable (crumbly) on it's own. Consider building SS or Aluminum form and fill that with your insulation mixture. Less portland will have a greater r value, and if your p-crete is filling a metal panel, then something like 10:1 will work well.