Objective 27.01 Explain basic arc welding procedures

Basic Arc Welding Procedures Metal should be cleaned before it is welded A grinder is the fastest way A wire brush or other methods may be used to remove paint, rust, dirt, oil, etc. Metal more than ¼” thick should be beveled at a 30 degree angle and placed 1/16” to 1/8” apart before two pieces are welded together

Types of Weld Joints Butt: two pieces of metal lying in the same place such as end-to-end or edge-to-edge in flat position T or “T”: two pieces of metal placed together to form a T, two pieces at a 90 angle to each other Fillet weld: used to fuse the two pieces permanently

Types of Weld Joints Lap: two pieces of metal overlap each other Corner: two pieces of metal make a 90 degree corner Edge: two pieces placed parallel to one another or stacked on top of each other

Welding position Welding position, metal thickness, and electrode size are used to determine amperage setting Amperage too low causes a narrow, high bead with poor penetration Amperage too high caused a flat bead with excessive spatter Correct amperage helps make a uniform bead with bead width and penetration depth equal to each other.