I am experimenting with an outdoor fireplace. Currently I am using a stainless steel tub from a washing machine. What I am noticing is that while the vessel gets hot it overall radiates very little. (unless fire is intense and vessel is glowing red hot). If I have line of sight to the fire/coals the radiated heat is substantial but drops off dramatically once below the rim of the vessel. I also use a ceramic coated clothes dryer drum placed on top to suppress sparks/embers at times and to safely