steel dome insulation??

[romstar]

Hello Im wondering.. if I wrap my 31 inch steel dome (propane tank) with ceramic blanket materiel a good wrap of chicken wire and 3 to 4 inches of perlite concrete is this the proper layering I need or is there a better way ? I"m just trying to get it right the first time..lol

[UtahBeehiver]

This is a tough one to answer. First of all we need to know what and how you are planning to use the oven. IMHO, the main issue with using a steel shell is that the steel will not provide any thermal mass (IE heat storage) that a refractory brick or concrete will provide, The added insulation will slow down the transmission of the BTUs from the inside of the dome to the outside but the insulation does not provide the thermal mass you need for extended cooking. That said, if you are looking at doing a few pizzas this set up will probably work, if you are looking at extended and multiple day cooking then you need to review having a steel dome. Good luck, others may chime in with different opinions.

[romstar]

ok! I see what your saying. I might use the steel dome as a liner for my brick work put the blanket(already bought it)over the bricks, a couple inches of pericreat, finish with a couple layers of portland.. If I get any cracks Ill just box the whole oven in with brick work and cover it with dirt or sand..Sound like a plan??

[UtahBeehiver]

There is a thread called other "oven types", some of which are steel dome/liners. Most are lined inside with firebrick although a couple with refractory concrete on the outside. How successful they are seems to vary from never hearing from them again to working okay. Search this thread and make you own decision.

[UtahBeehiver]

Update, I see you are already posting in Other Oven Types.

[romstar]

thank you!

[david s]

This is a tough one to answer. First of all we need to know what and how you are planning to use the oven. IMHO, the main issue with using a steel shell is that the steel will not provide any thermal mass (IE heat storage) that a refractory brick or concrete will provide, The added insulation will slow down the transmission of the BTUs from the inside of the dome to the outside but the insulation does not provide the thermal mass you need for extended cooking. That said, if you are looking at doing a few pizzas this set up will probably work, if you are looking at extended and multiple day cooking then you need to review having a steel dome. Good luck, others may chime in with different opinions.

To further clarify Russell’s point re thermal mass, steel is denser and way more conductive than brick or other refractory materials. It will provide thermal mass and because of its high conductivity, will both heat up and cool down far faster than brick or other refractory materials. You don’t say how thick the steel is though, so if it’s thin then it’s mass can’t store sufficient thermal mass on its own. If you want to add thermal mass then brick or refractory over the top is a good option. But be aware that the steel’s high conductivity means that it will get way hotter than brick or refractory sitting on top of it. This then leads of course to expansion against the cooler unexpanded refractory probably then leading to cracking. Not that it would really matter because the steel inner and the dome structure itself will hold it in place.