I've painted 3 or 4 airplanes with the poly fiber system (not aerothane) I do it in a 16' x24' garage stall. Have a window on one end that I put 4 layers of pourus cloth over to act as a filter, and raise the garage door on the other end up high enough to put a 20" box fan under the door. Close off the sides with plywood. The air goes through well enough that you never see a mist in the air, and I think the concentration of solvents is eliminated by that much air going through. Never had a problem blowing my self up (yet), but you can hardly notice the fumes when you run the fan steady. I do wear a good resperator, but not a fresh air system. JImChuk