Welding on Aluminum Alloy Bodies - Plug Welding
1. Plug Welding
1.
Removal and installation of aluminum parts:
Drill and remove the spot weld nugget using a 10 mm (0.39 in) diameter spot weld cutter.
For welding use the hole drilled when removing, or drill a new plug hole (?8-10 mm ( 0.31-0.39 in)).
2.
Cleaning and removal of aluminum surface oxidization layer:
Remove contamination and oil residue from the area to be welded using degreaser.
Sand off paint film using a disk sander (P80).
Remove the oxidized layer using a stainless wire brush.
3.
Firmly clamp the two panels being welded together. If there is excessive clearance, the weld will be defective.







4.
Plug Welding:
Clean the area to be welded with a stainless wire brush just before welding to remove any oxidation.
Use plug welding technique, starting from outside.
Start from about 15 mm (0.59 in) outside of the hole to preheat the area and ensure confirmation of adequate penetration.
When starting, hold the torch firmly and place your body in a comfortable, supported position which also allows a clear view of the welding area.
While checking for the penetration status, move the torch along the edge of the hole.
If you are new to aluminum plug welding, be careful not to allow excessive tip-to-work clearance.

Welding Double Layer (Two-Stack Panels):
Weld while aiming the torch at the edge of the hole on the mating surface between the upper and lower panels.
Check penetration:

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Depth of penetration should be 1/2-2/3 of the thickness of the bottom plate.
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Ripples or beads (round marks) appearing on the back surface are a proof of adequate penetration.

Welding Triple Layer (Three-Stack Panels):
Weld the mating surface of the middle panel and the lower panel.
5.
Be sure to check for cracks after welding.