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THE NEED FOR TESTS
The actual test employed depends upon the importance of the structure being welded. As pointed out at
the beginning of this discussion, quality welds may only be obtained from a machine having the necessary
functions, the machine must be kept in good working order and the same problem must be presented to the
machine on each weld (same material, contour & cleanliness). Obviously, the degree of quality control
desired will depend upon the product being weld, but sufficient control must be used to insure the desired
quality or the welds may fall apart.
If the above is to be accomplished, the control of these items must be delegated to someone in the
organization. In an aircraft plant, this might be a large department, while in the small plant, it might be
vested in the Foreman having charge of the welding department. In any case, the following points should
be considered in rules set up to govern them. Once set up, the rules should be enforced. They will result
in a superior product at a lower production cost in the long run.
THE POINTS TO BE CONSIDERED ARE:
A. Establish weld settings for each part produced. Once established, make a record on a suitable form-
listing ALL other control settings, electrode contour and the part number. When welding this part on future
production, he machine should reproduce the weld on the same setting, or a setting with minor variation.
The percentage allowable variation should be stated.
B. Establish what size, class and contour electrodes are to be used with each weld setting, and specify
how often the operator is to replace electrodes.
C. Establish procedure for checking the weld quality before starting a production run, and at predetermined
intervals during the production run.
D. Determine that the air line pressure and line power supplies to the machine are adequate, and that
other equipment is not added to the lines after installation, which affects the supplies to the machine.
E. Determine that the air line supplies clean air to the machine and establish responsibility for bleeding
the water filter (s) each day or more frequently, if found necessary.
F. Establish the responsibility for lubricating the machine with the proper oil and/or grease, including
adjustment of the air line lubricator.
G. Establish responsibility for seeing that the parts are cleaned properly, as such is necessary.
H. Establish responsibility for part fit up including periodic inspection.
I. Establish a training program for both operators and maintenance persons so that they may be thoroughly
familiar with the machine. Write ups such as this one are available to assist in this program period. When
H&H Resistance Welders personnel are at your facility, plan on having your personnel spend the entire
time with them to absorb as much knowledge as possible. Although a machine may look complicated to
those who are unfamiliar with it, most troubles encountered are of a minor nature and can be repaired by a
trained man in a short time, thus, eliminating “down time” in production to a great extent.