air gap between bottler frame and pan

[markct]

i built a rectangular bottler with a gas grill burner simular to what leader and others sell, i tried it and the burner seems to work great till ya set the pan down on it, then i guess it starves for air, i set 4 quarter inch spacers under the corners and tried it again and its much better, i was just wondering how much gap there is on the factory made ones if anyone has on they could look at

[Haynes Forest Products]

How does the spent gas and heat get out from under the pans. Could be that we just coverd this in another thread last week. If the frame/sides are to big you cause the unit starve for air. You might need a stack out the back. A small stack will alow the heat to build up but also let in air slowly. I had the same problem.