The “ins and outs” of sheetmetal repair for a rusty trunk floor


When it comes time to restore that classic muscle car, some sheetmetal repair is probably going to be required.

Most restorers can agree that the majority of repairs will almost always include the trunk floor, unless your car resided in a very dry climate like that found in the Southwest.

The recent restoration of a 1969 Dodge Charger by Jim Mott Restorations, of Kimberly, Idaho, included some major sheetmetal repair to the trunk floor. With Jim’s help, we decided to give readers a better understanding of how a trunk floor repair is accomplished and to provide some guidance to those “do-it-yourselfers” who might tackle a repair like this on their own.

Granted, not many garage enthusiasts have the equipment and know-how for this type of work, but with shop rates soaring, more and more enthusiasts are expanding out of their comfort zones, taking on tasks previously left to the professionals.

The big question for the restorer is how much sheetmetal should be removed? Our ’69 Charger had a vinyl top, which typically trapped moisture, causing rust and perforations around the front and rear windows. Most cars of the period clad in vinyl had serious issues with rust in the roof. Our ’69 Charger has some major perforations adjacent to the sail panels and along the bottom window channel, which naturally allowed water to enter the trunk, causing rust.

After having the car media blasted locally, Jim accessed the amount of sheetmetal work required for the restoration. “The only major repair would include the trunk floor,” he said. “Just a few spot repairs elsewhere.” We ordered a new two-piece trunk floor from Classic Industries.

Instead of replacing the entire floor with the new panel, Jim chose to remove and replace just that portion of the trunk floor that had damage. “I believe it’s best if we leave most of the original seams and spot welds intact whenever possible. That goes for the seam sealer as well. The cars just look more original.” Jim said a common mistake made by first time restorers is to cut out more original metal than necessary and then the repair becomes obvious.

We’ll carefully mark out the section of floor to be removed, drill out any spot welds in that section, and cut away the damaged portion. The cut-out section will be used as a pattern over the new replacement floor panel. A new piece will be cut out and welded in, seams ground smooth, filled, primed and painted.