What did I do wrong??

[jayjay]

We made a brick oven on a platform about 6 1/2 foot by about 8 foot.
We made the platform about 4 inches thick with cement. We let it cure
well and then made a hearth of about 3 x 4 foot, using red clay bricks.
Fire bricks are not available in the Philippines. We then built walls about a
clay block high and made an arch over the dome of the oven 18 inches high. The arch over the door is 15 inches high. The inside measurements of the oven are 2'8'' wide and three foot long to the door area. We have the door way about two foot wide and about 18 inches deep, or long. The inside measurement of the oven is 36 inches deep, plus the 18 inches to the edge of the door. We made the oven of clay bricks that are the only ones available on our island. We used minimal mortar. We encased the brick lined oven in 8 inches of cement made with about 8 bags of sand and gravel to one bag of cement. The walls of the oven are about 8 inches thick.
We let the oven dry a few weeks and then used several small curing fires over a week to cure the oven.
Yesterday we went for the gusto and fired the oven up. The char came off the walls and we then went to bake pizza. We took about two hours to get the materials for the pizza, made the dough and then went to bake the pizza.
The oven was not hot, but just warm. The outside walls of the oven were warm, the back barely warm, but the front of the oven was very warm, almost hot to the touch. We finally, got the pizza out, built a roaring fire and baked the pizza using the fire, not the oven itself. We burned wood for about three hours to heat the oven. I am wondering if we just need to burn more wood, or perhaps thicker pieces of wood. Most of the wood we did burn was mango and it was fairly well seasoned. The wood was 1 to 2 1/2 inches thick and about 12 to 18 inches long. We burned a lot, but did not get that much ashes when we swept the oven floor this morning. I did feel the front of the oven was still hot but the floor and back of the oven floor were only warm.
Were open to suggestion as to what we can do to get the oven in a better
position to cook pizza in the future.
A friend has a much thinner oven here and he says his oven stays hot for about 6 hours. I would like to bake Thanksgiving dinner in the oven, but now I am afraid to light it again.
I need help and encouragement.
If you need more information, please do not hessitate to ask. I will check backfor suggestions in a day or so. Thanks for any and all suggestions.
JJ
Philippines
email will get faster responses, pugoclaire@yahoo.com
Thanks folks...

[maver]

Jayjay - did you let the fire die down prior to trying to bake the pizza? To develop the heat needed for pizza it is cooked in an oven with a simultaneous large fire. It sounds like you constructed a barrel arch oven - you may have a little more challenge getting a large enough fire to make pizza while still having room for the pizza with the dimensions you describe. It also sounds like you made a high mass oven (8 inches thick) without any real insulation, so the heat is drawn into the walls of the oven. It likely will take much longer to bring this style of oven to heat compared to your friend's thin walled oven.

[CanuckJim]

Insulation?

Maver, JayJay,

I get the same feeling as Maver. If the oven has that much mass and no? insulation, then it will take much longer to heat up and will cool much faster than a thin-walled oven.

I hesitate to say this, JayJay, but is there any way you could build an exterior enclosure around your oven and insulate the space between with a non-flammable material?

A high mass oven needs to moderate, or rest, so the heat is evenly distributed through said mass.

Jim

[james]

I think this has a lot do with the number of times have you fired the oven. Even though the oven has been sitting for some time, and has been cured, it will take a series of growing fires to drive out the final moisture and really get cooking. I have gotten to where I can tell how well a Forno Bravo customer has cured and fired their oven when I meet them to cook in their oven the first time. An oven that still has moisture in the bricks, mortars and concrete just doesn't want to get hot.

On the insulation topic, I think you will want to do something around the oven. It will help the oven hold heat, and also, when the oven is cured and you are having hotter, longer fires, the exterior of the oven is going to get hot.

James