Fire Hazard

Clear the work area before welding. Combustible stuff like wood, paper or solvents has to go—sparks and spatter fly farther than you think. Especially in gaps and cavities it can smolder for a long time and only catch fire later, so check again after welding. For magnesium or titanium fires, water doesn't help—it only makes it worse—use dry sand or the right extinguishing powder. And if you have to work near easily ignitable material, keep a fire watch there.