Basic Welding - Part II/Welding Safety

MIG welding is the darling of the auto body repair industry. It offers the chief advantages of the other systems but has none of the disadvantages. The only drawbacks with MIG welding are that it cannot be use for brazing, and that it's not versatile enough to be used for unfreezing rusted-on bolts nor for cutting. MIG welding is based on the same principle of arc welding except that instead of having to feed a rod of metal into the joint, a MIG welder employs a spool of wire. An electric motor feeds the wire through a tube so that when the welder wants to weld the joint, s/he just pushes a button and the motor feeds the wire to the weld, slowly and steadily. In addition, the machine also feeds a gas that does not react with the weld to the area. This inert gas (argon, an argon/carbon-dioxide mix or just plain carbon dioxide) helps to cool the area, cutting down on distortion and the result is very few rippled panels. Cooling also means less burned paint, and you only have to strip out trim around the welded area itself. One of the few other drawbacks is that the metal must be clean and free of paint, otherwise the MIG welder sputters and "coughs."

In order to learning the technique of welding, seriously consider taking a class at your local technical school. It is well worth the effort to seek out professional training and instruction in whatever type of welding interests you. If you purchase welding equipment, study the written material supplied with it to familiarize yourself with the materials and procedures.

Warning: The flame produced by welding equipment is extremely bright. Never attempt to use this equipment without wearing a headshield. Never just use dark goggles because they are designed to protect only against the light of a gas flame. The intense light of an arc can cause permanent eye damage even through dark goggles. The headshield also protects the skin from harmful ultra-violet rays.

Caution: Always wear heavy cotton or leather overalls when welding. Wear heavy leather gloves to protect your hands and steel-toed or heavy leather boots to protect your feet. Cover all areas of your body when welding to avoid burns.

Caution: Always disconnect the vehicle's alternator on which you are working before arc-brazing or arc-welding because the current produced by this type of equipment will damage it.

Warning: Take special precautions when working with gas cylinders. These include, but are not limited to the following. Cylinders must be stored in dry, well-ventilated and fire-resistant area away from any source of fire or ignition, and protected from sunlight, ice, and snow. Cylinder valves must always be kept upright and closed, even when the cylinder is empty. Only trained personnel should handle cylinders - those who are fully aware of the hazards of working with cylinders and who are reliable. Immediately take damaged or leaking cylinders outside and notify the fire authorities and the supplier immediately. Do not come near a cylinder with a cigarette or open flame. Take care not to drop cylinders, knock them together or strike them. Never fill one cylinder from another. Every precaution should be taken to avoid damage to valves. Never wrench-shut a valve but just secure it enough to stop the gas. When changing cylinders, make sure all valves are closed and extinguish all open flames, including pilot lights. When a cylinder becomes empty, close its valve.