Page 156 - Welding of Aluminium and its Alloys

Table 7.4 Suggested weld preparations for MIG welding

Material Edge preparation Remarks
thickness
(mm)
1.6–4.8mm A backing bar gives
greater control of
penetration
6.4–9.5mm Weld from both
sides, sighting Vs
recommended
4.8–12.7mm 70° to 90° Suitable also for
positional welding,
when welded from
T both sides
T
/ 3
6.4–12.7mm 70° to 90° Flat aluminium backing
bar optional. One
or more runs from
each side. Back chipping
T recommended
T after first run
/ 3
6.4–19.1mm 60° One or more runs
from one side,
depending on thickness.
3.25mm Suitable also
rad for positional
welding
1.6–2.4mm
4.8mm
12.7–25.4mm 70° to 90° Up to 1.6mm root
gap. One or more
runs from each side.
Back-chipping
recommended after
first run
2.4mm
12.7–25.4mm 60°
2.4mm
3.25mm
rad

4.8mm
12.7–25.4mm 60°

6.4mm
rad

3.2mm