If there’s slag, you drag … sometimes.
When learning the stick or flux-cored welding process, you may hear the expression, “When there’s slag, you drag.” That’s true for welding in the flat or horizontal positions (using AWS nomenclature, that would be the 1G, 1F, 2G, and 2F positions). Dragging, or the “pull” or “backhand” technique, is when you point the end of the gun or stick rod away from the direction of travel.
With stick and flux-cored welding, slag is the solidified layer that forms on top of the weld. Dragging, coupled with keeping the arc on the leading edge of the weld puddle and maintaining a proper gun angle of 0 to 15 degrees, best ensures that the arc is directed into the base metal and avoids the slag.
If the push or forehand technique is used in the flat position, it increases the risk of trapping slag. Welders will say that “the puddle gets ahead of the arc” or “the puddle rolls over the slag and traps it.” Such an entrapment will be detected by X-ray or ultrasonic testing.
If you’re struggling with weld rejects and don’t know why this could be one reason. In some situations, you may have no choice but to push the weld. If you do, be sure to keep the arc on the leading edge of the puddle.
Now, for pushing or dragging in other welding positions, that’s a blog post for another time.