Metal lined

[Fred.C]

Hi All

I am about to build my pizza oven and having access to free metal I was going to build my oven using a metal shell and then insulating it with a mortal mix
The reason I was going to do this was the construction would be a lot easier for me being a Fitter/Boilermaker by trade
Also my Pizza oven will be build on a metal pole 2mt off the ground as I am limited with space on my deck, so therefore the oven will be at the edge of my deck.
Can any one tell me of any pitfalls with this plan, especially with having a metal lining inside the oven?

Regards
Fred

[taiwanpizzaman]

Re: Metal lined

I assume the insulation will be on the inside of the oven, because metals release gases (often poisonous) at high temperatures, but it all depends on the metal and its thickness etc. What about warping of the metal? With a thick enough high heat mortar on the inside, it would theoretically work. Good luck!
Colin

[jengineer]

Re: Metal lined

Who can pass up a bargain. Free metal? Got to find a use for it. Using a metal oven is nothing new. Many small mom & pop places uses a 55 gallon drum cut in half for BBQ. In your neck of the woods clean tanks can be converted into ovens. These oven probably have an peak operating temperature of around 500F/260C

Papua New Guinea - Drum Ovens

I agree that you will want this oven to be insulated on the inside and are essentially using the metal as a tortoise shell. A whole bunch of heat and wood will need to be used if you don’t insulate it. Your typical pizza oven cooks anywhere from 700 to 900F / 370 to 480C. Other than using direct heat from the wood the design intent is to also use the retained heat that is radiating from the side and bottom of the oven.

You are going into uncharted territory for this forum but we are more than willing to offer up our opinions to help you succeed. RMusa, in addition to doing a traditional oven has also ventured into the world of Tandoori’s. These cookers use high heat too and he pointed us to a few sites that offer help in the construction of that device. This site describes using a 5 gallon drum and plastering it with layers in insulating material (cement and glass) followed by fireclay/cement (RefMix?). One of my concerns with insulating the metal is the different rates of expansion that could occur between your insulation and the metal. If the metal heats up you could experience spalling (falling chucks of the “plaster’) That means your insulation has to be spot on and over-designed so that the heat is forced to stay on the inside of the oven and not allowed to migrate to the shell. In the tandoori setting spalling is not too big a deal as the chunks will fall to the bottom of the container.

Create those wonderful Indian curries by building your own tandoor with these easy instructions on how to build a Tandoor (an Indian clay oven)

welcome to the forum

[Xabia Jim]

Re: Metal lined

I had posted some pictures of clay oven liners they used in Spain. One of the pics was a metal exterior that held the liners as an option.

I agree that putting some masonry (refractory or firebricks) in the interior would be a good way to go....and knowing metalworking you would be able close it up around the inside.

good luck...post some pics as you make progress!

[janprimus]

Re: Metal lined

here are a couple of pics a friend back in Maine sent me from a country fair she attended last year. It sure looks cool!
http://myweb.facstaff.wwu.edu/chad/o...tal%20oven.JPG
http://myweb.facstaff.wwu.edu/chad/o...20interior.JPG
This certainly takes some math to get the dome right. Geez, it looks cool though...
Chad

[james]

Re: Metal lined

Chad,
Those are very cool -- they look with a traditional refractory oven on the inside, with that great metalwork (copper?) on the outside.

Is that right? I have never given metal work a try, and it looks fun. We've had some copper roofs, but a copper outer shell would be excellent.
James

[Alf]

Re: Metal lined

Formidable copper work, presumably the oven is a Le Panyol (as indicated by the sign board behind the oven) but to what effect. Here in the Uk the copper would go green due to our continues rain! However, well-polished copper always looks good. Well done for the excellent copper fabrication

Alf

[Fred.C]

Re: Metal lined

Thanks for all the information
This forum is truly amazing
Having read through alot of peoples ideas I have decided to build my oven out of bricks , in fact I am almost 3/4 the way though completion
I have been taking photos along the way and will post when I have time
I have set my self a deadline to make my first pizza in two week

[Paul Hagan]

Re: Metal lined

Hello I am also a Metal Fafricator and am building an oven of Steel
I modified the brick plans into steel and here is what I am doing. 3/16" steel inner wall 3000 degree KAOLWOOL refractory insulation in a 3" space and 3/16" steel outer wall. Base is 1/4" formed pan with insulation also. Am I going down the right road or am I setting my self up for failure? I appreciate your input

[dmun]

Re: Metal lined

Steel heats up quickly, and cools down quickly. I don`t think you are going to get brick oven like behavior, which depends on retained heat for cooking and porous masonry for moisture.

I don`t doubt you can cook in it, the world is full of steel ovens and barbeques, but I don`t seen any possible advantage to this plan.

[Alf]

Re: Metal lined

Folks who have gas and electric ovens buy pizza stones to put in the oven to cook their pizzas on. There are some manufactures in Germany who fabricate steel wood fired ovens, they to have a stone cooking floor. As Dmun pointed out you will be able to cook in it, but not for long periods. There is no thermal mass in the steel oven you propose, so there is no heat storage in the floor of the oven to really heat up and cook your pizza. Also the oven will not be able to cook roasts and casseroles because of the lack of heat storage. The last point is that brick ovens are self cleaning due to the heat generated within the oven a mild steel oven wont clean and will rust inside when not in use.

Alf

[Paul Hagan]

Re: Metal lined

David
I appreciate your advice as I am 75% complete on this project I will complete it and if it does not work Iwill scrap it. I will let you know what happens
Thanks Paul

[enz]

Re: Metal lined

For a steel oven to work like a brick oven, we would need to match the thermal mass and the heating characteristics of the brick. Thermal mass is not the problem. Looking at the ratios of specific heats and specific gravities, you need about half the thickness of steel to match the thermal mass of fire brick. The place you run into trouble is the emissivity of the steel, which is only about .25, while brick is around .68 . You would have a lot less of your fires heat absorbing into the thermal mass and actually take longer to achieve target temperature.



Enz

[Dutchoven]

Re: Metal lined

There is a portable oven design I have seen that is using a kind of half and half true brick/metal oven. It is manufactured of seamless steel and has a two piece oven floor tile(I think, have not seen pictures inside). As far as I know it is just a double skinned oven like you speak of Paul. That might give you some of what you look for. Perhaps buy a circular oven floor from James here at FB to fit in the bottom of your oven. I think if you hold your tongue right you might be able to make some pretty good pizzas and possibly even some flatbreads. As far as hearth breads I don't think it would work as it most likely would not hold the heat very long.
Good luck and I look forward to seeing some pictures of the oven as well as the resulting culnary creations.
Best
Dutch