Weld-Through Primer Guidelines: Subaru - UPDATE

Weld-through primers are generally a zinc-based product that are applied to the mating surfaces prior to welding. Corroding zinc forms zinc oxide which protects the steel. This is called sacrificial corrosion. For a quality weld to be made it’s required that the weld-through primer be removed from the direct weld zone before welding the joint when GMA welding. Many OEMs have a position on when and how to use weld-through primer or when it shouldn’t be utilized. Let’s see what Subaru recommends and where this information can be found.

Subaru does not call out the use of weld-through primer in their body repair manuals (BRM).

Previously, Subaru did not identify the use of weldable seam sealer in vehicles prior to 2024. However, the following information is an example found in the 2024 Subaru Impreza BRM under: Foreword ➤ Note ➤ Spotwelding. Subaru states:

  • "Apply a conductive rust preventive sealer to the mating surfaces targeted for spot welding.” This means to apply a weldable seam sealer between flanges when performing squeeze-type resistance spot welds.
  • "If the sealing is burned out by welding, be sure to take measures against water leakage in the burned area and he area around the burned area."

Subaru does not recommend a specific product or part number for a rust preventive sealer/weldable seam sealer.

Always use the vehicle-specific BRM to determine which type of welding is required for the repair you are performing. Failure to follow OEM procedures sacrifices the safety and quality of the repair.

For additional Subaru information, check out the Subaru OEM Information page.

Additional I-CAR Collision Repair News you may find helpful:


Related I-CAR Courses