I cooked the ITC coating on the furnace last night and at 8 psi we reached 2204 F/1205 C. My tank was getting pretty low - 8 psi was wide open - and we were getting "spitting" in one burners so I'll have to see what we can reach with a full tank. We also need to add the lines for air injection yet but we don't need that until we cast iron or try to make wootz steel. 

It does appear the insulation by the door shrunk more than we calculated. We'll need to fix that to eliminate the halo.