Problems with heating

Posted by RayF

Hi All,

I have been building my brick oven for a couple months now and I am to the point where I have begun test fires. I have the concrete cladding on for thermal mass but I haven't put the insulation on just yet.

Last night I tried firing the oven for 2 hours. I made the oven slightly bigger then Rado's plans call for (it's nine inches deeper). I burned a moderate sized fire in the middle of the oven for about 2 hours. The visible flames were just licking the dome ceiling for most of the burn, sometimes higher, sometimes lower.

Here is my concern: The dome only turned white directly over the fire and only then near the end of the burn. And that area of white bricks was only about 6 inches across. The oven itself didn't seem to get very hot inside. When the fire went out I could easily put my hand inside the oven and it didn't feel all that warm.

I have an oven thermometer and it never read above 200 degrees F. The concrete cladding did begin to get hot near the end of the burn (enough that I didn't want to keep my hand on it for long) but only at the top of the dome.

Do I have a problem? This sounds like the problem that Richard was posting about below. It sounds like I am using the same bricks as him although I haven't asked my brick seller specifically who makes the bricks. I do know that they are not insulating firebricks. They weigh about 7.5 lb each. However, I was able to cut them easily using a miter saw and a fiber cutting blade.

Could this just be a case of not firing it long enough? Maybe because I don't have insulation on it yet? Tonight I am going to build a much bigger fire inside and see what happens but I am hoping someone can reassure me that I am not going to have an oven I cannot cook in.

Thanks
Ray