Having suffered home fires at a young age I'm a lil anal bout that. My thing is welding. It's amazing how long it takes for a spark to smolder into a raging inferno. Biggest culprits...carpet insulation, shop rags, corrugated cardboard. Even more than welding sparks, grinding sparks will ignite stuff quickly due to their super-heated nature of flying through the air. We should also remember that Linseed oil and cotton rags are a wonderful recipe for spontaneous combustion. I never studied why, but a linseed oil rag will ignite when wadded up and cause one helluva fire. I try never to weld alone and keep a helper on "fire watch" making certain that run-away sparks don't cause problems through the night. I never weld something 1hr before leaving. Or I'll simply wait and have a coffee or whatever and assess what's done and what's next, simply to "tend" the area making sure nothing smolders. Many of us have worked on cars with automotive grade carpet insulation showing. Your best bet is to wet it down if it can't be removed from the area. This is more for the grinding aspect of things...you know, that last minute screw thread that's too long, or the thingamagig on the firewall that needs trimming before that hot new accy gets installed. Like the safety thing said...common sense. It goes a long way.
