Oven hearth surface will not get hot enough.

Posted by Rado (144.134.145.153) on September 15, 2004 at 08:04:40:

In Reply to: Oven hearth surface will not get hot enough. posted by Richard Stybak on September 14, 2004 at 11:50:43:

Richard, ceramic blankets can be expensive but are very effective insulation, used in higher heat applications e.g. in gas or electric heated atmosphere in kilns and furnances. Less dense ceramic blankets (pads) as back up heat insulation placed in order behind light weight *insulating firebricks Insulation will not absorb much heat, it has air spaces creating honeycomb effect and air is the best insulator.

*( insulating light in weight bricks are NOT the same bricks as heavy firebricks used for dome building in wood burning ovens. I've added a picture of such insulating brick and grog with description of it's use possibilities in the "Equivalent Materials and Sources" folder in my building cdrom- includes substitutes for fire clays, refractory mortars, firebricks, heat insulations.)

The dome is cold because this blanket layer won't let it soak through to the dense material. Then there is not heat in the dome which's meant to radiate back into the oven. Stainless steel is used mainly in conventional ovens with electric elements, where the oven temperature is constant. Behind the stainless steel casing is a firebrick which conducts heat all over evenly and insulation on the other side saves the energy.

Floor: here you should be fine with firebricks although addition of 2 inches plus into thickness would be beneficent preventing the floor cooling down too quickly. What kind of firebricks are there? Should be heavy and dense, not those insulating mentioned above.