Welding Consumables & Quality
- Select appropriate filler metals for stick and MIG welding based on Hendrickson L64 standards.
- Maintain weld quality by controlling fit-up gaps and crater completion.
- Implement specific preheat and restricted-zone protocols for axle structural integrity.
- Rod oven — Required for maintaining AWS E-7018 stick electrodes in a dry state to prevent hydrogen-related defects.
- MIG welder — Power source for applying AWS ER-70S-6 or optional ER-70S-3 wire for axle connections.
- Feeler gauges or calipers — Measure fit-up gaps to ensure they do not exceed the maximum allowable limit of 1/16".
- Temperature indicating sticks or infrared thermometer — Verify that axle connection preheat temperatures meet the manufacturer's specific instructions.
Stick: AWS E-7018 (oven dried). MIG wire: AWS ER-70S-6 standard, ER-70S-3 optional.
Welders should be qualified in the 2G position per AWS.
Avoid cold laps and undercuts; fill craters. Fit-up gaps must be no more than 1/16".
Follow the axle maker's preheat instructions for axle connections. Never weld in areas marked DO NOT WELD.
How It Works
Filler Metal Selection
Hendrickson L64 procedures specify AWS E-7018 stick electrodes, which must be oven dried. For MIG welding, AWS ER-70S-6 is the standard wire, though ER-70S-3 is an acceptable option.
Operator Qualification
To ensure structural integrity, welders must be qualified in the 2G position according to American Welding Society (AWS) standards before performing these procedures.
Structural Continuity and Fit-Up
Weld quality depends on strict adherence to fit-up tolerances. Gaps between components must not exceed 1/16". Additionally, craters must be filled and defects like cold laps or undercuts must be avoided to prevent stress risers.
Diagnostic Chart
| Symptom | Check | Spec / Expected | Likely cause & fix |
|---|---|---|---|
| Weld fit-up gap exceeds 1/16". | Measure the space between joining components prior to welding. | Fit-up gaps must be no more than 1/16". | Poor component preparation or alignment exceeding the maximum allowable gap. Basis: Hendrickson L64 Trailer Welding Procedures (Rev J) |
| Presence of cold laps or undercuts in the finished weld. | Perform visual inspection of the weld toe and transition zones. | Per the applicable manual | Improper travel speed, electrode angle, or heat settings resulting in a lack of fusion or base metal erosion. Basis: Hendrickson L64 Trailer Welding Procedures (Rev J) |
| Cracking in the axle connection zone. | Verify if preheat instructions were followed and if welding occurred in restricted zones. | Follow the axle maker's preheat instructions; Never weld in areas marked DO NOT WELD. | Failure to apply required preheat or welding in prohibited structural locations. Basis: Hendrickson L64 Trailer Welding Procedures (Rev J) |
| Unfilled craters at the end of weld beads. | Inspect the termination point of all weld segments. | Per the applicable manual | Breaking the arc too quickly without pausing to fill the weld pool at the end of the pass. Basis: Hendrickson L64 Trailer Welding Procedures (Rev J) |
At the Bay: Diagnose the Case
CASE 1 / 4
Weld fit-up gap exceeds 1/16".
- Test
- Compare
- Correct
Select the next check
Basis: Hendrickson L64 Trailer Welding Procedures (Rev J). A likely cause is a hypothesis; confirm it with the applicable service procedure before repair.
Common Bay Mistakes
- ✕ Using E-7018 electrodes that have not been kept in an oven.
- ✕ Allowing fit-up gaps to reach 1/8" or larger.
- ✕ Welding on axle components without checking for 'DO NOT WELD' markings.
- ✕ Substituting MIG wire types not listed in the L64 parameters.
- ✕ Neglecting preheat requirements for specific axle connections.
- ✕ Assigning 1G-only qualified welders to 2G required tasks.
Quick Check
Practice only — not scored.
Source: Hendrickson L64 Trailer Welding Procedures (Rev J) — Welding parameters