Old 09-14-2005, 10:29 AM
Join Date: Apr 2005
Location: Brazil
Posts: 306

I´ll try to clarify myself.
When I begun to built the oven, it grow up with the walls and I made the slab too (this means tooooo) big and surrounded by the walls. Then, I realized that this was a looot of thermal mass that would spend an eternity to be as hot as necessary. I faced with two solutions, discard the entire work and begin again (what could I did with a 3’x3’x1’ concrete/vermiculite broken mass on my backyard?) or build a entirely new slab over this old one. I decided by follow the second option.
BTW, I introduced other changes and went from barrel oven to domed one (Jim, James and folks were my inspiration and help, thanks again).
At this point I had a heavily concreted “table” that could not to be a “temperature drainer”.
I follow the slab construction as explained in the last reply, this is, from lower to upper, over the “concrete table” I put a alluminium sheet, followed by the fiberglass, then over it 2”of 8-1 vermiculite/cement mixture (isolation) and the 2” of concrete as thermal mass (isolated isle), finishing with the oven brick hearth resting on sand/clay.
I think that the above process is clear in the last reply pictures.
The thermocouple is located exactly in the middle of the circular hearth and below the fiberglass (between the fiberglass and the alluminium sheet).
The oven, when fired, take near of 1 to 1 ¼ of hour to reach the temperature to cook pizza and more two hours or so making several ones.
Before that, the dashes are retired, the oven floor is cleaned and the door is closed (if no cooking anything more).
The results are in the annexed archive (any one picked) in °F.
You could see that the line that shows the lower thermocouple is practically horizontal!


PS: Sorry “Abajo toda isolación” means “Below isolation”, that is ours.
Attached Thumbnails
Hope Pompeii Oven Photos Part 2-pizzatemp.jpg  
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Old 09-14-2005, 11:52 AM
dmun's Avatar
Join Date: Jul 2005
Location: New Jersey USA
Posts: 4,216
Default thanks,

I understand now. The thermocouple that doesn't show an increase until later is under two layers of insulation. That makes sense.

Thanks for taking these readings. It's shows oven behavior that we've only been guessing at.

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