In the past I have used box fans, squirrel cage fans, etc for pulling air and fumes out of a space during painting. I know they're not explosion proof, hence this thread. What do you use during painting? I have found a pretty cool way to build a fan to work, but is it all hype? How perfect of conditions do you have to have for the paint particles to catch on fire? Of course I'd rather be safe than sorry and I'm curious.