Scratches, chips and other inadequacies are just about unavoidable, but a careful repair job can be almost totally invisible. Here’s how to fix a paint scratch on your prized car, in a step by step.
Options for paint repair range from simple tinted waxes and As-Seen-On-TV wonder pens to multistage treatments matched to your car’s exact color. As someone who’s capable with a wrench. It costs a few bucks depending on which supplies you need, compared to a professional all-over repainting. This assembly of aerosol cans and sandpaper is as close as you can get to an appointment at the paint booth. Here’s how it works, and whether it’s worth it.
As with any thoughtful touch-up kit, there are a lot of materials. The box includes prep solvent, rubbing compound, the sandpaper of various grits, rubber gloves, a tack rag to pick up dust, pre-taped plastic to block untidy overspray (say blue painter’s tape for the car), and boxes of primer, base coat, and clear coat. It all proposes a lot of work, which turns out to be accurate.
Step 1: Abrasion
It feels very incorrect to lean into your fender with a folded piece of 180-grit, but that’s what you have to do. You make the scratch much, much shoddier before making it better. You may get big, horrible white blotches on the fender, door, hood, and rear quarter-panel. But it’s cleansing, in a way, to grind down to the bare metal in the name of making your car beautiful again.
Step 2: Priming
On to the sprays. First is the black-tinted sand-able primer. It fills in the sandpaper scores with something that looks like the original black, instantly reassuring me. You should add three coats to the metal in total, waiting five to ten minutes for each to dry before applying the next. This is a running subject of touch-up work: Devote two minutes of painting and then ten minutes waiting to do another two minutes of painting.
Step 3: Coating
Primer gives way to the base coat, meaning more aerosol cans. Each application seals in the pigment and protective layers underneath. Between sprays, you sand with ever-finer paper. By the end, you’re wet-sanding with 1,500-grit, which feels flatter than a sheet of construction paper. At each intermission, you get closer to a factory-finish gloss. The last clear coat confirms your work with a shiny shell.
Step 4: Results
The clear coat dries overnight, and you can hit your handiwork with the rubbing compound to bring out the shine. And shine it does, which brings us to an unforeseen dilemma: The touch-up work looks better than the original paint. Unavoidably, nine layers of new paint look better than decades-old factory black. For the job overall, say, success. In fact, too much success. The directives say an all-over wax will help it blend. Final step: Give it with the detour buffer and hope it blends.
Anatomy of a Scratch
Unless the car you’re repairing is over 20 years old or was custom-painted, the paint is almost certainly a clear-coated catalyzed enamel. Falsely hardened by toxic chemicals, it’s stable within hours of factory application.
On the other hand, the paint you’re applying, whether it’s a primer, color or clear, is a lacquer. Lacquers dry for the reason that the solvent evaporates, leaving the solids behind. While they may sense hard and be sand-able within a few minutes, they will continue to shrink for a while. Let lacquers to dry at least overnight so they can shrink in size before you add another coat. If you need numerous coats to build up the paint film to full thickness for a repair, one coat a day is best. Of course, be safe. The amounts of solvents used are small but work in a well-ventilated area. Make sure to degrease the area with solvent before starting.