WELDING OPERATIONS I - OD1651 - LESSON 1/TASK 2
(4) Crater cracks can be eliminated by the backstep and overlap
procedures or by using the electrode hesitation and drawback technique.
Crater cracks formed in the initial weld passes should be chipped out
before additional weld metal is applied. Then they can be welded out
successfully by the subsequent passes.
As a precaution, string beads
should be used on the initial passes.
On subsequent passes, do not
weave the electrode more than 2 1/2 electrode core wire diameters. The
efficiency of the joint welded by this method depends upon good fusion
to the base metal and side walls of the slots in the butt strap.
(5) If straightening is necessary, use a hammer only on the soft side
of face hardened armor, on the butt strap, or on the plug welds.
Do
not hammer on the face hardened side. As a rule, force should not be
applied to straighten face hardened armor if the applied force will
produce tension on the face hardened side.
(6) When two or more butt straps are used to repair irregular cracks
or to make patch welds, the butt straps are welded together for
additional strength as shown in figure 41.
FIGURE 41.
BUTT STRAP.
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