1968 Ford F-100 Patch Panel Installation - The Bumpside Build-Off

Another tool that has its place are pneumatic sheetmetal shears. These are good for cutting long, straight lines or gentle curves, but they aren't the best for intricate maneuvers.

Once you get used to the body saw, it can also be used for straight cuts, but it requires a steady set of hands. When initially cutting out the patch panel, I leave 1/16-1/8-inch extra material around the edge, which usually gets ground down during fitment but will leave a nice tight gap for butt welding.

Once I was happy with the fit of the patch panel into the floor, I took my angle grinder and put a 3-inch Power Loc-style "red" 3M Scotch-Brite pad on it to strip the black sealer of the sheetmetal from NPD. The red 3M Scotch-Brite pad is far less abrasive than 36-grit sanding discs and won't remove material from the edge of the piece, which is already thin and tricky to weld.

While I personally prefer TIG welding to MIG welding for most jobs, the MIG still comes in handy and could be used to weld the patch panel in place with good results. I used our Miller MIG welder to tack weld the patch panel in since I was using my other hand to line up the butt joint between the pieces so they would sit flush once tacked. Notice the small even gap around the patch panel? That's what careful fitting and trimming will yield and what we're striving for. Of course, cutting a patch bigger than the hole and slapping it in there so it overlaps the edges and welding it up would be easy and quick, but wouldn't you shy away from buying a truck with work like that done to it?

With the new patch panel from NPD tacked securely in place, I went back in and started welding it for good with my Miller Dynasty 200 TIG welder turned down to about 50 amps. When welding most patch panels, remember to skip around the piece in a star pattern and wait for each weld to cool before starting another. Compressed air can reduce cooling time.

Again, using my favorite angle grinder and 36-grit sanding discs, I carefully ground down the welds. Remember, sheetmetal is thin, and a grinder used in a small area can generate enough heat to warp it quickly. While this isn't as big of an issue on floorpans, it's good to practice the same work habits whether you'll see the work or not. Plus, it'll be that much easier when you do have to work on a fender or hood!

With a little more finish grinding work, it'll be hard to tell anything was ever done! If you have rust in your Ford truck, call National Parts Depot today and get started on your own patch panels!