I built this up-draft gasser. boiler and all in all it works great, But, the panels i have to seperate the chambers only last about 4-6months? I tried cordierite 3/4thick and corelite 1inch thick, both cracked?? I been told from the color on them it runs 1700* to 2000* they are 12x16inch and 14x16inch in size. I am thinking of just putting steel or stainless but this would melt or break down,right? I read about Silcon carbide but cost alot and did not seen to have good specs? Any ideas of what to use? The piece you see red is part of chamber[choker] The flame is almost clear it so hot, I think it just gets to hot in there,i get a bluesh purple type flame or clear most of time,i tried to adj. air and cooled fire off but?