Tis But a Scratch: Misadventures in Automotive Scratch Repair

Dual Action Car Polisher comes with 3 different pads that are best suited for different areas depending on the job at hand. The scratch was small, maybe half an inch long. Hard to even see unless you knew where to look. But once you knew, it was the only thing you could see. It was all I could see, anyway. If you’re looking for that final touch to add a rich gloss and shine to your car’s paintwork, carnauba wax is a popular choice.

I had only had the car for two weeks when the scratch appeared. I’d gassed up just once by the time I saw it, right there on the hood. How could it have happened? A mishap at the car wash? A passerby I’d wronged? Some kind of deranged animal? It wasn’t from another car or falling debris, that was for sure. But what could have left this blemish, marring my beautiful new Mazda CX-5 with less than 300 miles on the odometer, leaving behind a scratch so deep I could run my fingernail inside it? From the looks of it, it went all the way down to the primer.

I guessed it didn’t matter. The real question was how to get rid of it.

My quest to remove the scratch took me first to my local car wash and detailing center, who always seem to do good work. The guy with the clipboard said that for $100 they’d hand-wax it and try to buff it out. I crossed my fingers, but after the detailing the scratch was still there. I asked the technician, a term I use extremely lightly, to take another look. They squirted some polish onto a rag, rubbed it for a second and shrugged. Nothing we can do, the scratch is too deep. I would need to take more drastic action.

The aftermath of that encounter led me to the one place where I knew I could find a solution: The internet. And as I expected, I quickly found there was no shortage of tactics and products that promised to remove scratches from your vehicle, be they either tiny or deep.

Car Scratch Fever

Even cursory research online will take you down a rabbit hole that will reveal myriad approaches to fixing a scratch. One YouTube video showed I could just spray WD-40 on the scratch to make it disappear. Another site said I could just rub toothpaste on it. A lot of these amounted to very temporary fixes or last resort repairs, and if you spend more time doing the research you’ll find scratch repair ultimately boils down to a few different approaches, all of which I eventually tested.

Before I explain them, first you have to understand how automotive paint works. A modern car has three levels of paint on top of the bare metal: primer, then the base color, then the clear coat, which is the thickest layer of the three. A small or shallow scratch is deemed as one that doesn’t break through the clear coat and into the paint, whereas a large or deep scratch impacts the paint, the primer, or the bare metal. The further down the scratch, the harder it is to repair but, as Novato, California-based car restorer Walter Jensen said to me, “Every scratch is different,” adding that a scratch can be quite complex, shallow on one end, deep in the middle, and shallow again on the other side. “Honestly, a scratch is harder to deal with than a dent,” he said.

Small scratches can usually be rubbed out with polishing compound. The rule of thumb is that if your fingernail doesn’t catch on the scratch, it’s just a superficial clear coat scratch that can be smoothed out and made invisible. Scratches like these show because the light catches the side of a V-shaped groove in the clear coat. The reflection is so strong that it can look white, particularly on a car with dark-colored paint, said Mike Pennington, a veteran director at Meguiar’s, which makes a well-known line of car paint repair and daily care products. The goal with light scratches is simply to smooth out that V into a wide valley, so it doesn’t catch the light, effectively making the scratch invisible.

For deeper scratches, polish isn’t abrasive enough to fix the problem. For a deep scratch that’s visible even when you wet it down, you have to physically sand the area with a solid abrasive, such as sandpaper. You can use hand power or a mechanical sander—and here’s where you will find the widest variety of approaches and products. For the worst scratches, I learned, you have to fill the V-shaped groove with paint and/or filler, like Bondo, then sand and polish.

Wax On, Wax Off

Before I tackled my own car, I decided to experiment on a test panel I acquired at the local junkyard. I scratched it up with box cutter, making scratches of various depths, and then put products from four different companies to task to try to remove them.

I started with the simplest of the bunch, a collection of light-duty products from Turtle Wax, including Rubbing Compound, Polishing Compound, Scratch & Swirl Remover, and Carnauba Liquid Wax (total value about $20). All four of these come in the form of runny white goo that is applied with a cloth; pay close attention or you won’t know what product you’re using. While together they did a fair job at hiding the lightest of surface scratches at a distance, under most lighting conditions even minor scratches remained clearly visible.

Pennington had turned me on to Meguiar’s Ultimate Compound, Polish, and Liquid Wax (total cost about $35), which I put to task on the same scratches for my next test, again working by hand. The results were marginally better than Turtle Wax, but just barely. “If the scratch isn’t out after a few passes, you need to turn to a machine,” said Pennington.

Sure enough, not until I fired up Meguiar’s DA Power System ($54 total) did I see markedly improved results. The DA Power System is an impressive rotary polishing system that attaches to a standard drill, moving in an orbital (not strictly circular) motion, ensuring more even coverage. With a little electric muscle, the DA system indeed made the lighter scratches virtually invisible, though moderate and deeper ones remained.

But why weren’t these products working? “Most products won’t completely eliminate the scratch, but we can make it less noticeable,” said Kevin Ansell, a senior engineer at 3M (which also owns Meguiar’s). The key was to get some sanding action involved on that scratch. Given the depth of some of my test scratches, Ansell suggested the 3M Trizact Precision Scratch Kit ($20), an all-in-one system that also uses a drill and promises to remove light and medium scratches. The “simple three step process” includes sanding by hand with sandpaper, using a drill attachment to apply rubbing compound, and finally using the drill again to apply polish.

Here you’re actually sanding down the clear coat on your car, which is scary as hell, but it quickly became clear some sanding was required to significantly improve most of my test scratches. The Trizact sandpaper was pretty miraculous on that front. After a couple of minutes of wet sanding, I’d made substantial headway on the moderate scratches on my panel, though I’d clearly dulled the paint, taking the shiny clear coat down to a hazy matte. Buffing with compound and then polish with the included drill attachments shined everything up, and sure enough my light scratches were gone, with moderate ones almost invisible. The system definitively improved the deepest scratches, though they were still somewhat visible. My only beef with the kit was that while you can reuse the drill pads, the rubbing compound and polish come in non-resealable packets and aren’t suitable for significant reuse. Also, the sandpaper provided is tiny, just 2 inches square. It’s not just hard to work with at that size, it’s also sure to quickly become spent.

A similar but even less costly approach can be found from Quixx Repair Systems, in a kit that works through a “German engineered process called Plastic Deformation.” The all-in-one-box Quixx 00070-US Paint Scratch Remover Kit is just $14, extremely minimal. I have to give points to Quixx for its easy and thorough instructions, easily the best of this lot. It classifies scratches into four categories, and customizes removal instructions for each. The kit includes four tiny strips of sandpaper, two cloths, polish, and a finishing paste. Alas, the system paled in performance next to 3M’s kit. While Quixx did a decent job at hiding light scratches, its sandpaper was simply powerless against larger ones.

Painting by Numbers

I was still not convinced the scratch on my new car would come out with these methods, and I asked Jensen about dealing with the deepest scratches. He was somber: The deepest scratches invariably need to be filled with paint, as all the sanding in the world simply won’t make a difference. I’d painted over scratches with touch-up kits in the past and acknowledged that things looked even worse afterwards. Jensen said I probably did it all wrong.

“Don’t use the brush in the vial,” he said. “You have to put the paint on with something like a sharpened toothpick, dabbing it just inside the scratch, not on top of it. You have to get it just right. You want to use almost no paint at all. Never put touch-up paint on top of good paint. Just do it very carefully, very slowly, letting it dry in between coats.” After painting (and perhaps a tiny strip of clear coat on top of that), it could then be smoothed and polished using one of the above tools.

I ordered some touch-up paint based on my car’s color code and got to work practicing on my test panel.

Finding the right painting implement was a challenge. A sharpened toothpick was OK, but it just didn’t hold paint well. I scoured the house for something plastic and sharp, and ended up settling on a little spike used for punching holes in jack-o’-lanterns. Painstakingly I used the nubbin to dot touch-up paint directly into the scratches, but I quickly found that getting paint only on the inside was basically impossible. I experimented with combinations of paint, clear coat, and sanding, and eventually concluded that the most prudent course of action was to apply paint, wipe off any excess (as any residue could be sanded and polished away later), apply a thin amount of clear coat, and wipe off the excess again. The key, I’d been told, was to try to get everything level, since it was jagged edges that made the scratch visible, though Pennington had suggested that even if the paint wasn’t perfectly aligned, it could be carefully sanded down.

After quite a few practice runs on the test panel, I felt I was ready enough for the main event. I washed the panel area on my Mazda, let it dry overnight, and applied my first dots of color. Despite my best efforts, I was making a mess of it. Partly that was because it was becoming evident the real scratch was irregular and jagged, with a variable depth that didn’t respond the same way my straighter test scratches did. Every scratch truly was different, as Jensen had said.

I wiped off the excess paint, leaving behind a slightly obvious smear, but figured I could fix that later. It was the same story with the clear coat. It just wouldn’t sink into the scratch, leaving behind a bulbous, highly visible ridge. Again I wiped off the excess, and now had a quite obvious, messy smear of paint on my hood.

I let it dry, then took to the 3M Trizact sandpaper, wrapping it around the end of a paint stirrer to minimize the surface area I was sanding. After getting everything nice and wet, I slowly sanded the area until the paint smear was gone, trying to get the paint on the scratch itself reasonably smooth. This was slow going, and the clear coat was starting to fade badly, leaving behind a significant area of dullness. After nearly five minutes of light sanding, the surface still wasn’t completely smooth, and I started to panic a bit, worrying I was damaging the clear coat irreparably.

Finally out of cautious prudence I stopped and turned to Meguiar’s compound, polish, and wax, applied with the DA Power System. After the first round of compound and polish, the paint was still hazy, so I did both treatments a second time, allowing the paste to sit on the car for a few minutes before wiping it off this time. The shine mercifully restored, I gave the whole area a coat of wax and called it a day. Total cost for everything I actually used in the repair: About $130.

The results? Well, now, instead of a scratch, I have a slightly raised area that looks marginally darker than the rest of the car, as if the paint isn’t a perfect match. It’s less noticeable, to be sure—pictures don’t really tell the story—but if you know where to look, the scratch is still easy to find. Am I happy with the results? Not entirely, and I’m sure someone more seasoned than me, even after a week of experiments and tinkering, could have done a better job. I am at least comforted that the area, now covered by paint, won’t rust, though I’m concerned about lasting damage to the clear coat, and what that might mean down the road.

But perhaps the whole endeavor had been foolish. As Jensen told me, “If it’s a daily driver, and you’re taking it around town, leaving it in parking lots … it’s going to get scratched. Fixing it just may not be worth the trouble.” Click here now we do the repair for a scratch in your car.

Maybe he was right, but what fun is that? Now about that chip in my windshield…