Whether you decide to purchase the panel or fabricate your patch from sheet steel, it will need to be welded into the hole. We tend to prefer a wire feed mig-welder for this operation, set on a low voltage and wire-speed to create less heat. We then tack the patch in place and stitch-weld the panel in varying areas around the perimeter so the heat generated by the welding process doesn’t warp our patch or the adjacent metal. There are tools that will crimp the metal adjacent to the patch in order to form a recess, but making a nice tight fitting patch and butt-welding it in place is the preferred method. If priming the bare metal, be sure to use a weld-through primer in areas that will be welded.
Once the metal patch is welded in place, the welds can be ground flush and the panel can be massaged with a hammer and dolly, but the repair will likely need a skim coat of body filler before being primed and painted. We’ve all heard claims that “this or that car is all metal, no filler”. And while these claims may or may not be true, we’ve found most repairs, no matter how skilful the body man or how accurate the patch, require at least a little fill to ensure straightness of the paintjob.
Speaking of paint, the best time to repair the rust in your Mopar is before you paint it, not afterwards. But if a small rust spot or hole does appear after your car is painted, don’t panic. Chances are you, a friend, or a competent body shop can repair the affected area and paint it to match without having to repaint the entire vehicle. Over time our cars will rust, but it’s nice to know that with the right parts, products, and procedures our Mopars can stay looking their best indefinitely.