[Kenw]

Welding on 18 gage patch panel on a car. if there is a small gap between the metals that the weld need to fill the gap the weld will crack in time

[Otto Nobedder]

Welcome, Ken,

I selected "approve post", and one of the admins beat me to it by seconds, I suppose. Took a second to figure out what was going on...

Another issue with gaps in patch panels is the additional shrinkage, adding distortion to the repair. The solution is planishing, ideally hammering the weld from both sides at the same time. This both relieves stress and "stretches" the heat-affected metal, reducing distortion. If you have poor access to the back side, it can be done with a hammer and dolly.

Steve S