Objective 27.01

1
Objective 27.01

• Explain basic arc welding procedures

2
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

3
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

4
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

5
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.