Miller Electric 300, 225 manual Lap Joints, Tee Joints, Welding Troubleshooting, Porosity

8-9. Lap Joints

30° Or Less

30° Or Less

1Electrode

2Single-Layer Fillet Weld Move electrode in circular motion.

3Multi-Layer Fillet Weld

1 1

2	3
Single-Layer Fillet Weld	Multi-Layer Fillet Weld

Weld a second layer when a larger fillet is needed. Remove slag before making another weld pass. Weld both sides of joint for maximum strength.

S-0063 / S-0064

8-10. Tee Joints

1

45°

Or Less

2

2

1 Electrode

12 Fillet Weld

Keep arc short and move at definite rate of speed. Hold electrode as

	shown to provide fusion into the
	corner. Square edge of the weld
	surface.
	For maximum strength weld both
	sides of upright section.
3	3 Multi-Layer Deposits
	Weld a second layer or more when
	a larger fillet is needed. Use any of
	the weaving patterns shown in Sec-
	tion 8-7. Remove slag before mak-
	ing another weld pass.
	S-0069 / S-0058-A / S-0061

B. Welding Troubleshooting

Table 6-1. Porosity

Porosity − small cavities or holes resulting from gas pockets in weld metal.

Possible Causes	Corrective Actions
Arc length too long.	Reduce arc length.
Damp electrode.	Use dry electrode.
Workpiece dirty.	Remove all grease, oil, moisture, rust, paint, coatings, slag, and dirt from work surface before
	welding.
	OM-316 Page 35