Weld-Through Primer Guidelines: Mercedes-Benz

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 Mercedes-Benz recommends and where this information can be found.

This information, along with other part preparation guidelines, can be found in the vehicle-specific body repair manual. Mercedes-Benz:

  • refers to weld-through primer as zinc dust paint.
  • has their own brand of weld-through primer that needs to be used.
  • says to treat all bare sheet metals parts when welding.
  • specifies to treat weld seams and riveted joints on both sides.
  • warns not to use weld-through primer for painting outer surfaces.

Also, note that weld-through primer should not be used on aluminum.

Use the vehicle-specific body repair manuals to determine which type of welding is required for the repair you are performing. Failure to follow OEM procedures will sacrifice the safety and quality of the repair.

For additional Mercedes-Benz information, check out the Mercedes-Benz OEM Information page.

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