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Red Seal Auto Body Technician study materials
Red Seal Auto Body Technician study resources

Red Seal Auto Body Technician: Welding, Cutting, and Joining

Red Seal Auto Body Technician · Work through your exam, one topic at a time.

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Welding, Cutting, and Joining

Welding, Cutting, and Joining

This domain tests joining methods and their limits. Expect GMAW (MIG), squeeze-type resistance spot welding (STRSW), GTAW (TIG) for aluminum, oxy-acetylene and plasma cutting, brazing, adhesive bonding, self-piercing rivets, and flow-drill screws. The exam stresses matching the OEM join, not choosing the fastest method.

Core rules

  • Match the OEM joining method: STRSW for many factory spot welds, rivet bonding or adhesives where specified, GMAW only where approved.
  • Weld quality requires clean metal, correct wire and gas, proper current, and penetration without porosity, undercut, or excessive spatter.
  • Galvanized steel must be stripped at the weld zone and welded with fume extraction; zinc oxide fume can cause metal-fume fever.
  • Aluminum welding uses dedicated consumables, 100% argon shielding gas, and a push technique; keep aluminum separate from steel tooling.
  • UHSS and boron parts may prohibit MIG welding or require specific procedures; check before welding.
  • Test welds on scrap of the same material and thickness; inspect and adjust before welding the vehicle.
  • Cutting with plasma or oxy-acetylene creates heat and fume; protect adjacent systems and remove interior trim.

Worked example

A quarter panel is being replaced on a vehicle with factory STRSW joints and adhesive. The shop's STRSW welder is unavailable, so a technician proposes MIG welding every seam. Reasoning: MIG welding may not duplicate the OEM joint and can overheat adjacent UHSS. The correct choice is to use the OEM-approved alternative, often rivet bonding with structural adhesive and the specified rivet pattern, or reschedule until the STRSW equipment is available. The technician must also restore weld-through primer and seam sealer.

Traps

  • MIG welding all joints because it is familiar.
  • Using the wrong shielding gas for aluminum.
  • Welding galvanized metal without stripping and ventilation.
  • Skipping test welds.
  • Forgetting corrosion protection between joined panels.
  • Using a rivet where the OEM requires a weld, or vice versa.