2
INCOMPLETE PENETRATION
This type of defect is found in any
of three ways: 1) When
the weld bead does not penetrate the entire thickness of the base plate.
2) When two opposing
weld beads do not interpenetrate. 3) When
the weld bead does not penetrate the toe of a fillet weld but only bridges across
it. Welding current
has the greatest effect on penetration. Incomplete penetration is usually caused
by the use of too
low a welding current and can be eliminated by simply increasing the amperage.
Other causes can be
the use of too slow a travel speed and an incorrect torch angle. Both will allow
the molten weld metal to roll
in front of the arc, acting as a cushion to prevent penetration. The arc must
be kept on the leading edge of
the weld puddle. Figure
10-1 - Examples of Lack of Penetration
