4. Once the rusted area is...
4. Once the rusted area is cut away, like the lower quarter panel of this Coronet (you can now see the trunk drop extensions), there’s a good chance you’ll find more rust on the underlying structure. Here, we had to fabricate a patch for the trunk extensions so we’d have something to weld our outer patch to.
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.
5. With the rusted area cut...
5. With the rusted area cut away, a metal patch will need to be fabricated to fit the area. New sheet metal is available from most body shop supply stores, or you can do like we do and cut the pieces you need from wrecked panels at the local body shop.
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.
6. For extensively rusted...
6. For extensively rusted areas, or to ensure the patch has the correct body lines and contours, another option is to purchase the entire panel from a company like Auto Metal Direct, then cut the pieces you need for your repairs.
7. Small holes, like those...
7. Small holes, like those for trim or tiny rust holes, can often be repaired by welding the hole closed. Using a piece of brass on the back side of the hole makes welding easier. The weld won’t stick to the brass.
8.
When welding metal patches...
8.
When welding metal patches in place, stitch welding is the preferred method as making short welds across from each other and slowly working around the patch generally won’t warp the patch or adjacent metal.
9. We prefer to use Vice-Grip...
9. We prefer to use Vice-Grip style clamps to hold the repair pieces in place, but if necessary and in a pinch, we have used sheet metal screws to hold a patch in place until it’s welded. Once welded, the screws are removed and the holes can be welded shut.
10. After welding the patch...
10. After welding the patch completely and grinding down the welds, the area can be straightened initially with a hammer and dolly. Chances are the area will need at least a skim-coat of body filler as well to ensure complete straightness before paint is applied.
11. Once the patched area...
11. Once the patched area is welded and skimmed with body filler, block sanding is required to ensure the panel is straight. This process involves using finer and finer grades of sandpaper, and multiple coats of primer to fill small imperfections and low spots. Once sanded, the area can be final primed and prepped for paint. After a final coat of primer, the repaired area should be invisible and smooth to the touch. With new metal in place, water will have a difficult time getting under the paint to cause future problems. mm