I don't know if this is something to think about but I thought I'd throw it out there. the body shop I worked in years back had a booth where the fan blade was inside of the exhaust duct and the motor was on the outside of the duct. I know ive seen on the spray can of 2k its very flammable. so I don't know if its dangerous to use an electric fan on the inside of the booth for exhaust. is it safe with all the fumes being drawn past the exposed electric motor with arcing brushes ? if that makes any sense