Preparations for MAG and spot-welding

WARNING: This page is about a different car, the 2013 BMW 550i GT, 2012 BMW 550i GT, 2011 BMW 550i GT, and 2010 BMW 550i GT. However, it is still accessible from the selected car via links, so may be relevant.

Remove the paint coating in an area of approx. 30 mm around the weld seam or spot.
- The zinc coating underneath must be removed during the MAG welding operation.
- It is not necessary to remove the zinc coating underneath during spot-welding.
Remove the paint coating on the reverse side of the weld seam or spot.
- Contaminants will otherwise enter the weld pool via the root of the weld seam.
- An insufficient electron flow prevents an optimum spot-weld joint.
Coat all metal overlaps and weld spot flanges with welding primer.
To determine the optimum electrode contact force for spot-welding, carry out spot-weld shear tests on sample metal sheets.
In order to keep the electron flow short during MAG welding on the body, you must if possible attach the ground terminal directly to the component to be welded.