Fillet welding is used to join panels of different thickness or when added strength is required.
1.
Cleaning and removal of oxidized layer:
Remove contamination and oil content from the area to be welded using degreaser.
Sand off paint film using a disk sender (P80).
Remove the oxidized layer using a stainless wire brush.
Remove oxidized layer from the hatched areas.
2.
Upper and lower panels must be positioned tightly against each other.
FORWARD WELDING
3.
Welding:
Clean the welding area with a stainless wire brush just before welding.
In fillet welding, penetration occurs quickly at the edge of the upper panel and slowly in the middle of the lower panel.
The current should be slightly lower than for butt welding. Check for proper penetration through lower plate while welding.
Weld while holding the torch with an angle (approximately 10 degrees) against the welded surface. In particular, when the thickness is different between the upper and lower panels, pay extra attention to the penetration condition while welding.
The beads should be of the same height as the panel thickness or slightly higher. When the thickness of the upper and lower panels is different, adjusting to the thin panel helps to reduce distortion.
