Welding on closed containers, such as tanks, drums, or pipes, can cause them to blow up. Sparks can fly off from the welding arc. The flying sparks, hot work-piece, and hot equipment can cause fires and burns. Accidental contact of electrode to metal objects can cause sparks, explosion, overheating, or fire. Check and be sure the area is safe before doing any welding.
Protect yourself and others from flying sparks and hot metal.
Do not weld where flying sparks can strike flammable material.
Remove all flammables within 35 ft (10.7 m) of the welding arc. If this is not possible, tightly cover them with approved covers.
Be alert that welding sparks and hot materials from welding can easily go through small cracks and openings to adjacent areas.
Watch for fire, and keep a fire extinguisher nearby.
Be aware that welding on a ceiling, floor, bulkhead, or partition can cause fire on the hidden side.
Do not weld on closed containers such as tanks, drums, or pipes, unless they are properly prepared according to AWS F4.1 (see Safety Standards).
Connect work cable to the work as close to the welding area as practical to prevent welding current from traveling long, possibly unknown paths and causing electric shock and fire hazards.
Do not use welder to thaw frozen pipes.
Remove stick electrode from holder or cut off welding wire at contact tip when not in use.