I am new to this heat management stuff so I'm sure I haven't tried everything, but I haven't been able to get much over 550 F. My Oven is 60 inches dia with 4" of unexpanded perlite. I have fired it up with what I would consider a medium to large fire with flames lapping up to the top of the dome. It takes about 2 hrs to get it nice and hot. Most of the time I have the door closed during heat-up. Having the door open keeps the flames going. Am wondering if I should keep the door open during heat-up. This seems counter productive. The door is a loosely fitting piece of metal plate which gets very hot, pot holder hot. The dome gets slightly warm to the touch, less than 150 F. I haven't really fired it up to a roaring fire yet so I guess that's the next step. How long should it take to get to temp? Also I am just measuring with an oven thermometer that only goes to 600 F. Never got the entire dome white hot. Any suggestions are certainly appreciated.