- Car Care & Maintenance
How to Keep Your Car from Rusting Out
When I was a kid, I remember hearing my father complain about how the wheel wells on his old pickup truck were rusting out and how bad it was for the rest of the metal on the vehicle. I didn't know why rust was a bad thing when I was that young, but as I got older I dealt with rust issues of my own—on my own car. Rust, or iron oxide as it is technically called, spreads relatively quickly and can damage not just the look of something, but also the functionality. Worse still, tetanus can live on rust, which is what makes rusty nails in a garage so dangerous should you happen to cut yourself on one.
I eventually had to trade in that station wagon, because the metal on the chassis had rusted so much that the crumple zones were no longer as protective as they once were. I did some research about how to prevent rust and found that there were quite a few options, but that some of them are meant for more industrial jobs.
How Does Rust Happen?
We've probably all seen photos of what the Titanic looked like after it had spent a few years on the floor of the ocean. Instead of its once-lustrous steel, the ship was coated in green and orange. These patches on metal come from being exposed to the elements—air, water, and salt, just to name a few. Oxygen and water on metal creates iron oxide, which basically dissolves the metal underneath it. That's why on a brand new car, there's no rust to be found. Once it's scratched, either from an accident, scraping a curb while parking, or anything else, the metal is unprotected. The paint is gone, leaving bare metal on its own to fight off decay.
How Can You Stop Rust Once It's Started?
When there were just a few patches of rust on my old Ford wagon, I read up on how to stop it, and most people who have covered the subject pointed out that of visible rust, you're only actually seeing 30 percent of what's there. In other words, the corrosion goes deeper than the surface. Unfortunately, while you can sand off as much rust as you see and paint over it as best you can—either with auto body paint or simple spray paint, depending on how picky you are about what your car looks like—the problem will most likely rear its ugly head again. In order to really prevent the spread of rust, you either have to sand off all of the damage, which could compromise the metal's structural integrity, or replace the part altogether, which is how I learned about rust prevention methods. I figured, if I was going to spend some money to replace the parts that needed it most, I should at least try to stop the same problem from occurring again.
Rust Prevention Methods
In terms of your car, the easiest method for preventing rust is washing it regularly, including the undercarriage and inside the wheel wells. Since those parts of the car are exposed most to the street and dirt, they get the dirtiest. That dirt can hold moisture against the metal and corrode it pretty quickly. But there are more specific things I learned about when trying to get to the bottom of the old rust dilemma, things that companies use to keep their equipment and machinery working in tip top shape for as long as possible. I first learned about a process called acid passivation, which basically turns the metal into a nonreactive surface—in other words, even when exposed to water and air, it won't rust. This works by exposing the metal to either nitric or citric acid, which in turn exposes chromium to the surface. The chromium then reacts with the air to form a very, very thin (just a few molecules deep) surface that is no longer vulnerable to the elements. It sounded pretty interesting, and I also learned that there's an even more intensive process called electropolishing, which not only makes the surface non-reactive to air and water, but also smooths out even the smallest of inconsistencies on the surface. Since it smooths everything out, it's even more effective at preventing rust from happening because the surface is uniform without any nicks. This is also great for pieces of metal that bend, like springs. When a spring rusts, it can break, since rust eats through the parts that get the most use.
Prevention Is Better than Fixing Rust
Obviously, preventing the problem from happening altogether is better in the long run, because it's more effective at actually stopping the problem. If something starts to rust out and you catch it early enough, you can still alleviate the issue, though.