CHAPTER 4: DEVELOPING WELD SCHEDULES
DUAL PULSE 125
STORED ENERGY RESISTANCE WELDING POWER SUPPLY
4-4 990-270
Evaluate the Weld
Use pliers to peel the welded materials apart. A satisfactory weld will show residual material pulled
from one material to the other. Tearing of base material around the weld nugget indicates a material
failure, not a weld failure. Electrode sticking and/or "spitting" should define a weld as unsatisfactory.
Weak Weld
If the parts pull apart easily, or there is little or no residual material pulled, the weld is weak. Increase
the %ENERGY in increments of 1% to 2%. The actual Weld Strength is a user defined specification.
If the weld is satisfactory, make numerous welds, using the exact physical set-up which is planned for
the production line, to determine if the process is repeatable. Then you should properly document your
Weld Schedule and COPY Schedule 0 to one of the 125DP's permanent Schedules (1 - 7). See
Chapter 3.
Electrode Sticking
Electrode sticking includes burning, sparking, and "blown welds." These problems indicate that either
the %ENERGY is too high or the electrode force is too low. Refer to figure 4-1.
Examine the electrode face. Resurface it if it is pitted, contaminated or burned. See Electrode
Maintenance later in this chapter. Increase electrode force and/or decrease %ENERGY. Repeat Make a
Weld.
Causes of Imperfect Welds
Table 4-1 lists the effects of the basic welding parameters on weld quality.
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