Body damage is one of the inevitable realities of owning a truck. At least, it is if you use said truck like it was meant to be used. Cab corners are all too often the victims of well-intended forays to the hardware store or trail, and common enough that many are willing to write them off as signs of character, or the scars of a hard day's work. Still, dented corners are objectively far from pretty and, worse, a veritable breeding ground for rust. And that's never pretty, no matter how you use your truck.
First, find a replacement cab corner. Depending on the year of the truck, you can either go to a junkyard and cut out the patch you need or check with aftermarket suppliers to see if any supply replacement sheetmetal.
Assess the area you need to replace. If rust is the problem, then you want to be sure to have a solid surface to attach your new metal to. If the problem is body damage, then make sure that your patch will cover all the damage.
Take your patch panel and trim it with a cut-off wheel or air saw to fit the area you want to replace. Place the patch over the original panel and use a permanent marker to outline the area on the truck you want to remove. The goal is to make the patch panel fit as perfectly as possible.
Cut out the damaged area on the truck. Make sure to cut less than you need to start, then slowly trim away the original metal until the patch panel can perfectly fit in the hole.
Using the grinder with the sanding attachment, grind the paint off of the edges of both the patch panel and the truck to ensure a clean weld. Once the metal is clean, hold the patch panel in place with magnets and once it is lined up perfectly, tack weld the patch in four corners.
The key now is to very slowly and carefully weld the replacement panel in place. If you weld the panel too fast, it will get hot and warp the metal. The more time you take, the better result you will get.
Once the entire panel is welded in place, grind down the welds smooth with the body.
Using a spreader, mix the body filler on a scrap piece of cardboard and apply a layer to the patch panel. Once the filler is dry, sand it down with a sanding block and 180-grit sandpaper to rough in a shape.
Keep applying filler until the panel is roughed in. Sand the area again with 180-grit sandpaper,, then 500- and 800-grit to get a good basis for the primer.
Spray the primer onto the area. Now just take the truck to a professional body shop so they can blend the color correctly and your truck will be all set.
