WELDING OPERATIONS I - OD1651 - LESSON 1/TASK 1
more than 15 degrees above the horizontal for proper molten metal
control. The arc should be held short to obtain good fusion and
penetration.
(b) When welding tee joints in the vertical position, the joint
should be started at the bottom and welded upward and the
electrode should be moved in a triangular weaving motion as shown
in figure 22, view A, on the previous page.
A slight pause in
the weave, at the points indicated, will improve the sidewall
penetration and provide good fusion at the root of the joint.
1 If the weld metal should overheat, the electrode should
be
quickly shifted away from the crater without breaking the arc
as
shown in figure 22, view B. This will permit the molten metal
to
solidify without running downward.
The electrode should
be
returned immediately to the crater of the weld in order
to
maintain the desired size of the weld.
2 When more than one pass is necessary to make a tee weld,
either of the weaving motions shown in figure 22, views C and D,
may be used. A slight pause at the end of the weave will develop
good fusion without undercutting at the edges of the plates.
(c) To make welds on lap joints in the vertical position, the
electrode should be moved in a triangular weaving motion as shown
in figure 22, view E.
The same procedure for making the tee
joint is used except the electrode is directed toward the
vertical plate marked "G" in figure 22, view E. The arc should
be held short, and the pause at the surface of plate "G" should
be slightly longer. Care should be taken not to undercut either
of the plates or to allow the molten metal to overlap at the
edges of the weave.
(d) Lap joints in the vertical position on heavy plate require
more than one layer of metal.
The deposited bead should be
thoroughly cleaned and subsequent beads deposited as shown in
figure 22, view F.
i. Overhead
Position
Welding
(figure
23
on
the
following
page).
(1) Bead Welds.
The overhead position is the most difficult
position to weld in because it
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