The use of improper welding techniques causes many weld
and/or frame failures. The following information points out potential areas
of difficulty and provides some general guidelines for successful frame
welding.
Most weld failures occur at the end of the weld in areas of the frame
that are under high stress. Eliminate the end of a weld in order to reduce
failures. Make a hole or a slot in the part to be attached. Use a fillet
in order to weld around a slot or a plug weld. Do not leave a notch at
the end of a weld.
Over welding can be harmful, especially if you are welding in an area
that receives high concentrations of stress.
Small cracks in a crossmember may be welded.
When Welding:
| • | The frame is covered with a protective wax coating. Use a wire
brush in order to remove any concentration of wax before welding. When finished,
recoat the area with new wax. |
| • | Do not use oxyacetylene welding equipment. |
| • | Whenever possible, use smaller diameter electrodes and make several
passes. This is preferred to using a large diameter electrode and making fewer
passes. |
| • | Do not use more heat than is necessary in order to give good penetration. |
| • | Make sure that scale is removed from each successive pass. |
| • | If repairing a crack, grind the surface of the weld flush with
the parent material. |
| • | When mounting accessories, do not weld across the flanges. |
| • | When mounting accessories, do not weld within 19 mm (3/4 in)
of a flange. |
| • | Do not weld up to the edge of a part being welded to a frame.
Leave 6 mm (0.25 in) between the end of the weld and the edge
of the part. |
| • | Do not weld cast brackets to the frame. |
| • | Do not weld the flanges of cracked reinforcements and base rails
together. |
| • | Do not attach the ground cable to the engine. Connect the welding
machine ground cables as close to the working area as possible. |
| • | Disconnect the vehicle battery. |
| • | Do not get the welding cables near the vehicle wiring. Avoid direct
contact between the welding cables and any part of the vehicle. |
