UPS delivered it, I opened it and started a fire.  Burned for the next six hours.  Spring clean-up,  shag bark hickory, silver maple, pine and hickory nuts.  If it was laying in my yard I burned it.  It was full of hot ash at six p.m.  At ten p.m. ash was almost totally gone, only a few embers left.  Started again next day,  four hours, same results.  Had a very hot fire in it for two days.  It changed the color of the top ring form the heat but that was it.  Also it left no burn marks in my yard.  Great engineering.  Next time will be for fun (wine ) and cooking something.