Car Rust: What Causes It and How to Prevent It

car with rust

A shiny and clean car is sure to give a good first impression. But not the same can be said for all.

Rust on a car’s exterior doesn’t necessarily affect its overall performance, but it’s an eyesore. Having rust on your vehicle means two things: neglect or age. If you’re guilty of the former, then it’s time to make a change of habits.

Like any piece of machinery, cars need regular maintenance for tires, engine, oil, and check engine light services, to name a few. The care itself can already cost any car owner. To prevent extra costs, take preventative measures for your car’s exterior.

Causes of Rust on a Car’s Exterior

The car’s exterior is the first and most exposed to extreme temperatures and weather changes. A car’s exterior is often made with an anti-rust coating on it. However, with frequent exposure to some elements, the coating is compromised and will be unable to withstand the formation of rust. Knowing what can cause rusting on a car’s surface gives insight into how to prevent these from happening.

  • Chipped Paint

When a car’s paint chips or disappears over time due to scratches, dents, and even prolonged exposure to the sun, the surface becomes vulnerable to decay. The paint serves as a protective layer against natural elements and corrosive materials. Without it, it leaves the car’s bare surface vulnerable and prone to rusting.

  • Salt

It’s common practice for car owners to put road salt on their vehicles. This is to help melt away the snow that’s gathered on the car. Although this seems like the easiest and fastest way to get rid of snow on your vehicle, it’s actually harmful. As the snow melts, the salt can find its way to the surface. Salt makes metals more prone to rusting, and indeed exposure to melted snow isn’t going to help.

  • Rain

It’s common knowledge that water can contribute to rusting. Unfortunately, your car is no exception to the rule. When the exterior is exposed to rain, it can trigger the process of oxidation. Oxidation occurs when the surface reacts with water and oxygen.

wind shield with rainwater

Ways to Prevent Rusting

Exterior decay is a relatively normal sign of age. But other times, it’s a sign of neglect. With some simple tips and to-dos, you don’t just prevent decay but also prolong your exterior’s condition.

  • Wash Your Car

Washing your car is the bare minimum, but it’s often underestimated. It does more than maintain a shiny, clean look. Washing your car gets rid of corrosive materials, debris, salts, and more. By doing this regularly, the build-up of corrosive materials is prevented. Don’t forget to polish and wax too!

  • Inspect Drain Holes

Your car has its own deference to help prevent rusting too. But just like any other part of it, it’s going to need regular maintenance and inspection. Check out the drain holes found along the bottoms of car doors. The drain holes’ job is to let water and melted snow out since water can still seep past the door seal. Drain holes are also located in other parts of the car, such as the rocker panels, sunroof, and more. These will also need to be maintained and inspected from time to time so that they can continue functioning well.

  • Protect Your Car From the Rain

As mentioned, prolonged and frequent exposure to rain and direct sunlight can hurt the exterior of a car. To prevent premature rusting, park your car under shade or anywhere that it can be protected from natural elements and extreme temperatures. The prevention is easy to do and costs nothing compared to repairs. Parking your car in the garage could be a habit you should start doing.

The Solution

The ultimate solution would be to rid the surface of rust, be it by sanding or replacing the affected area entirely. For smaller areas with rust, sand these down until they are bare metal. Afterward, have the areas repainted with the same color of paint as your car. This is generally how it’s done for DIYs and rust repair kits available in the market. But if you don’t have much experience on bodywork or the affected areas are bigger than what you’re able to manage, consider taking it to a body shop.


Don’t expect rust repair to be easy. Naturally, the cure is more demanding than prevention and costly at that. These are simple yet easy-to-do tips anyone can do. But if you’re already doing them, you’re on the right track.

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