Agricultural Engineering Safety Lesson Plan: Arc, TIG, and MIG Welding Safety

OBJECTIVE

Identify and use the safety practices that should be observed when arc welding.

MATERIALS

AC (alternating current) welder, DC (direct current) welder, AC/DC welder, MIG welder, TIG welder and all accessories.

KEY POINTS AND SUPPORTING INFORMATION

1. Protect yourself. Wear welding gloves, helmet, leather apron, welding chaps, leather shoes, and eye protection to help prevent weld burns and injury. The welder and all observers must wear welding helmets with the appropriate filter lens strength for the type of welding being done. Arc welding requires a No. 10 to 12 filter lens. MIG welding requires at least a No. 10 shaded lens. TIG welding requires a No. 11 or 12 shaded filter lens.
2. Weld in a well-ventilated area. Welding fumes should be ventilated away from the person welding, not across the welder's face. Remember that shielding gases are asphyxiants, and welding fumes are harmful. Work in well-ventilated areas to prevent suffocation or fume sickness.
3. Never wear synthetic fiber clothing or weld with flammables in your pocket. Synthetic fibers are highly flammable. If ignited by a welding spark, flammable (i.e. matches, butane lighters, fuel sticks, etc.) could cause serious burns. Do not allow bystanders to smoke in the welding area.
4. Avoid electrical shock. Make certain that the electrode holder and all electrical connections and cables are properly insulated. Check to see that the welder is properly grounded. Do not dip the electrode holder in water to cool it because this practice may result in electrical shock. Never weld in damp locations because of the shock hazard. When operating a MIG welder, never touch and electrical connection, bare wire, work, or a machine part which may cause electrical shock. Gloves help to insulate against possible shock. When TIG welding never touch the tungsten electrode with the filler rod. The tungsten electrode is charged with electric current which may charge the filler rod and shock the person welding. The current potential at the tungsten electrode is at the arc voltage level or higher. A shock from the electrode could be deadly.
5. Wear hearing protection with TIG pulsed power and high current settings. Power pulses cause the arc to emit sound waves. Because the noise produced may be loud at high current pulses, hearing protection should be worn.
6. Adjust the TIG high frequency unit only within the limits recommended by the manufacturer. This will help reduce the possibility of shock and body burns.
7. Protect welding cables. Keep the cables from coming in contact with hot metal and sharp edges. Do not drive over cables. When welding, avoid wrapping electrode cables around your body.
8. Use both hands. To reduce fatigue, use both hands for welding.
9. Handle hot metal with pliers or tongs. Submerge hot metal completely in water to prevent steam burns.
10. Do not allow electrode to stick. If the electrode sticks, cut off the switch, allow electrode to cool, and then break it loose with your gloved hand.
11. Prevent burns. Never allow the hot electrode or electrode holder to touch bare skin. Avoid letting the electrode touch the grounded cable. Remove hot metal from the work area when you are finished welding to prevent burns to others.
12. Secure work. Use a welding table with a positioner to hold welds securely in place. Clamps and vises can be used to hold odd-shaped work or field work. Securing work will also prevent injury from accidental dropping of metal on your feet or body.