hehe, my mom gets pissed when i hang dollar bills in the vents and sees them flapping around....
my dad as a few drums laying around. he acutally just called me and gave me the sizes. all are radius then lenght
3'2x5'1
3' 5'7
4' 6'1
5'2 6'2
4' 5'7
then we have some monster 7' by 22' or something. huge. fuel tank from a gas station.
you think around is going to be effecient? or don't care long as it's not propane being burned?
for my door we came across this safe. it's huge. the door weighs 500lbs, and it's only 25x28. it's almost 10" thick at the center.. not cast iron, but it shouldn't warp..... but not sure how to cut holes in it for the draft. torch isn't gonig to do it. it would take days to drill.....
Couldn't you put the blower below the door??? Assuming your leaving room in the bottom for ash buildup, I'm sure you could fab up somekind of smaller area in the inside to allow for air to flow in and at the same time keep the ashes out of the way...
I would say that round should be the most efficient, however I'm no expert on the whole thing, round just eliminates fab cost and welding, also reducing total pieces of steel needing to be sheared... just easier overall to build,