I did not know where to put this but I thought there may be some interest from forum members so this seemed like the safest spot to share. I have been playing with the idea in my head for some time and still cannot decide if I am going to mod my old shed or just buy a new one for the project but in the mean time I spent a day in the fab shop and whipped out this little hot box to put heat in the sauna. Just a 12x12x24" square tube I cut off a drop. The door has a damper intake that works on a dial made from a structural steel bolt and nut. I put a removable 1/2 baffle in to divert the outflow and force the heat across the top panel to warm the rock tray and used 4 structual bolts and nuts for the legs to make them adjustable for leveling. In the pics it just has about 3 or 4' of 8" set on top for the test fire and she is burning clean - no smoke!! For the sauna I will probably run 5" stove pipe or even a piece of 5x1/4 pipe that I have at the shop. All in all I think it will work well for quick, hot fires that last an hour or two at a time. Just a summer project so I will continue to update as I make progress as long as there is interest. Should be fun next winter getting a good sweat on!!