steel template and inside liner

[aussie bricky]

I have made my pizza oven template out of plate steel ..I want to leave the steel inside the oven when finnished. Do you think having the oven lined with steel inside will effect the dynamics of the oven?? I will post a pic of the steel template// lining on my page.

[Wiley]

Re: steel template and inside liner

aussie brickie,
Yes, I think leaving the steel plate will effect the performance of your finished WFO.

I think you will find that it heats faster and obtains a more even heat distribution than straight bricks or cast refractory. This is because the steel has a higher conductivity of heat than does the straight refractory. Thus the direct heating of the plate from the fire more quickly spreads the heat to a larger area and more efficiently transfers the heat to the underlying refractory than heating the refractory alone and having that heated refractory conduct the heat to surrounding refractory. Likewise when shutting up a steel plate lined WFO oven to equalize the temperature when baking "equalization" of internal heat occurs more quickly. The better re-radiation of the steel plate lining also will cause the hearth to heat quicker during fire-up.

You should find that you use less wood to get to temperature as overall efficiency of absorption and transmission is better with the steel than with straight bricks or cast refractory.

MKlingles wrote:
"
You are correct that steel is a much better conductor of heat than fire brick. The conductivity of steel is ~43, and firebrick is ~1.4. So, about 30x better conductor of heat!.

The steel is probably black. So, it is absorbing and re-radiating heat, not so much reflecting it. It would quickly heat through and radiate the heat into the brick and into the oven equally.

I agree with your notion that the heat spreads through the steel very quickly then radiates into the brick much more evenly. My dome clears (burns off the soot) first on the top of the oven and takes a while longer to clear down the sides.

Also that 30x greater conductivity means the steel absorbs heat from the hot gases from the fire 30x more efficiently then the brick. So you have less heat flowing up your chimney.

Cheers!"

Hope this helps,
Wiley

[GianniFocaccia]

Re: steel template and inside liner

My initial thoughts are that a steel-lined oven will provide a hearth that is way too hot to cook pizza on. I like the concept of the steel encouraging the underlying hearth bricks to heat up more quickly than an all-brick hearth (I'm looking for a similar result from my soapstone floor).

But what effect will the steel have on the cooling curve of the hearth? Steel cools off much more quickly than brick or even wood for that matter. It would seem conceivable that steel would act as a wick in cooling the hearth bricks despite the fact the door is on.

[Wiley]

Re: steel template and inside liner

GianniFocaccia,
So far empirical results for two WFOs that I have personal experience with (my own Steel Dome Oven and Dented Bouy, which is used commercially) have not shown any problem with the steel liner making the brick hearth too hot to cook pizza upon. Note in both these WFOs the hearth are still fire brick.

As for the liner causing the oven to cool down more rapidly (with the door on): Anything at the same temp as the WFO (and inside) actually acts as another heat reservoir. Heat loss is thru the door and the insulation, otherwise it is captive. The better the insulation the longer it is captive.

Hope this helps,
Wiley

[GianniFocaccia]

Re: steel template and inside liner

Wiley,

My error: I misconstrued aussie bricky's description as leaving the steel template literally inside the dome and acting as the floor. I agree - anything, especially 1/4" plate steel that remains within an oven's insulation and enclosure would act as yet another heat-radiating and heat-retaining material.
John

[aussie bricky]

Re: steel template and inside liner

thank you very much for this information, it has eased my mind. when i said do you think the steel liner will affect the dynamics i was thinking in a negative way but it is clear now that it will be in a posative way.
regards stephen

[ajejeje]

Re: steel template and inside liner

Wow, you all have a great point of view.