A) Preparation:
The edges must be clean, degreased and free of all traces of paint.
Refer to the Autogenous Welding Table on page 22 for the choice of tip, filler
metal, distance between parts, welding torch positions and filler metal rod diame-
ters.
Keep the tip of the cone 2 to 3 mm from the joint in all operations.
B) Tacking:
Before embarking on autogenous welding, the parts must be tacked to keep them
firm.
Tacking involves melting welding points 2 to 3 mm long on the edges of the parts
with or without a filler metal deposit.
The distance between each point is equal to 20 times the thickness of the parts to
be joined.
Following the following tacking order:
Flat parts
C) Welding:
It is advisable to apply a small weld bead, known as the heel, 5 to 6 mm long once
the parts have been tacked (see Fig. 1). Start this heel fully on the sheet and stop
it at the end of the assembly.
Heel
Fig. 1
Implementation:
Tubes
forward movement
Start of welding set back
from the end of the heel.
54
OXYPOWER
Fig. 2
®