Oven temp profile

[Tscarborough]

Nope, but the FB plans are by far the most superior design and instructions available.

[Tscarborough]

I have said it before, but it worth repeating. I built an oven because I wanted to build a Timbrel arch: Guastavino tile - Wikipedia, the free encyclopedia, and an oven seemed to be the most practical thing for me to build incorporating the Timbrel arch construction.

It so happened that doing research I came across this site, and used the specifications for the insulation on my oven. I advise everyone who asks (and they do, almost daily) that the FB plans are the optimal for their oven, and if they want to have an oven without building it themselves that the FB products are the best value by far.

[lwood]

We all now know what is possible. There is always our next oven Jay...

[davmorr]

My oven is a 42 inch Pompeii built this past summer and fall to the insulation specifications in the FB plans. The cavity around the oven is filled with perlite, with about 18 inches over the top. My metal door is insulated with 2 inches of ceramic board (left over from the board used to insulate the hearth) and 2 inches of loose fiberglass batting. At ambient air temperatures of plus or minus zero F, my oven is producing a hearth temperature in the 500º to high 600's range, approximately 14 to 18 hours after closing the door after baking pizzas. I'm finding that the temps in the 600º plus range are achieved when I bring the oven back up to 1,000º plus after baking pizza. So, white ash, followed by a couple of hours baking pizzas when the hearth temp drops to 600º or so, then refiring to 1,000º and letting it burn down for a half hour or so before closing it up, seems to produce the saturation required to produce at least two following days of useable baking, roasting and slow cooking temperatures.

I'm keeping data on my firings over three days in order to get the feel for my oven's performance. But, so far, I'm really pleased. Thanks to FB for the plans. They worked for me.

[Drewaudio]

Hi Davmorr,

I'm new to this forum and am about halfway through my oven construction so please excuse my silly question.... Do you remove the burning coals before you seal the oven or do you just leave them in there?

Kind Regards,
Andrew

[david s]

Depends if you either need the space or need the oven floor clean, but there is no problem leaving them there. If I'm doing a roast I only fire for one hour then just push the coals aside and slide in the oven tray. The oven is not completely saturated with heat, but it's plenty to cook the roast and uses very little fuel.

[lwood]

Drewaudio, if you are baking bread you take out the coals. Great numbers davmorr, you did it right. Another data point. It appears that if you follow the FB design, you can expect to get 500F degree heat for at least 12 to 18 hours. I still believe the major factors in heat retention are the efficiency of the door and the insulation.

[davmorr]

I don't remove the coals until 15 to 20 minutes prior to bread baking, when I remove them and swab the hearth. I replace the door to allow the hearth to equalize. After 15 to 20 minutes pass, I use the FB infrared thermometer to measure center hearth and dome temperatures. My oven seems to run about 50º plus or minus difference between the dome and hearth at 12 to 14 hours after firing and saturation. Although I'm keeping records of temperatures at different locations within the oven, I'm using only the center hearth temperature for making the decision on whether to load bread and the probable length of the bake. I'm still learning my oven, but it has been a lot of fun.

[Lburou]

Originally Posted by davmorr

My oven is a 42 inch Pompeii built this past summer and fall to the insulation specifications in the FB plans. The cavity around the oven is filled with perlite, with about 18 inches over the top. My metal door is insulated with 2 inches of ceramic board (left over from the board used to insulate the hearth) and 2 inches of loose fiberglass batting....snip....

Your experience is encouraging us to 'keep to the plans'.

I read above, that you put the perlite over the oven....I'm assuming the perlite went on over a ceramic insulation layer placed in contact with the dome? Forgive me for asking the obvious, but I'd like to duplicate your results, and every detail can be crucial, espesially if the detail is overlooked

Les, your numbers are enviable too

[Faith In Virginia]

Well it took a while. I have many thermocouples and an IR so this is from two points point of the oven. First is the floor one inch down and the second is a wall one inch in. I'll be making a graph for all the points involved

Sunday we did a preheat on the oven so
Monday 10:40 am floor 245 wall 258
Fired the oven
Monday 4:12 pm floor 722 wall 675
Baked 59 lbs of bread with floor swabbing
Monday 9:42 pm floor 392 wall 432
Closed door
Tuesday 9:38 am floor 344 wall 369
Wednesday 9.40 am floor 254 wall 273
Thursday 9:46 am floor 193 wall 206
Friday 9:40 am floor 146 wall 156
Saturday 9:40 am floor 120 wall 128