Rust is a recurring issue for car owners, especially if they have multiple vehicles that can’t all share the same garage space. Rust isn’t just bad for your vehicle’s esthetic. It can also compromise your vehicle’s structural integrity if it goes on for too long, as rust eats through metal over time.

As vehicles age, they become more susceptible to rust, so you can’t avoid it forever. For this reason, it’s essential to know how to fix significant rust on a car. 

Fortunately, you don’t have to hire an expensive rust removal service or rebuild part of your car to get rid of large rust patches. Let’s break down the process of how to fix major rust on a car. 

Rust is impossible to avoid since it’s a natural chemical process that occurs when iron, a core component of steel, comes into contact with moisture and oxygen. The earth’s atmosphere has plenty of water and oxygen to spare, making it a common element of our ecosystem. Any steel exposed to the air will eventually corrode due to a process called oxidation.

However, some types of steel take longer to corrode than others. Furthermore, modern cars are manufactured with a far more durable galvanized steel, a corrosion-resistant material.

Your car’s paint also plays a pivotal role in preventing rust damage. It physically prevents oxygen and water from coming in contact with the steel beneath its surface.

Generally speaking, as long as you regularly wax your car and take care of it, you probably won’t have to worry much about rust. But if you have an old car you want to fix up, or your vehicle has accumulated rust from being left outside for months, there are ways you can repair the corrosion without replacing the steel wholesale.

If you want to fix significant rust spots, you’ll need specific tools that are critical to getting the job done. These include:

Don’t forget safety equipment! You should always use safety goggles, gloves, and a respirator or surgical mask at a bare minimum when performing rust removal.

Once you have gathered all your materials, you’ll need to prepare your car for rust repair. 

To do this, start by bringing your car to a suitable location for the task, like an outdoor space or the interior of a clean garage. Pick a place where other objects won’t get dirty as you sand away rust and paint.

After deciding upon a suitable location, the real work begins. Start by covering every non-rusty inch of your car’s surface. You don’t want to accidentally sand down any of the good paint or wax on your vehicle. You can cover your vehicle with a material like newspaper, for instance. Simply use the masking tape mentioned above to secure the newspaper (or any other covering solution) to the surface of your car.

If you plan to use an angle grinder to get rid of a significant amount of rust, consider utilizing a fire-resistant and durable protective covering for your car - since sparks will be flying in the immediate area.

Now that you have prepared the vehicle accordingly, it's time to start removing rust. 

Use sandpaper to sand down the paint and rust on the affected surface. The idea is to keep using the sandpaper until you reach the bare steel underneath the paint. When removing rust, you have to get rid of all of it before you paint again. Otherwise, you’ll just delay the corrosion process, and more rust will begin to appear all too quickly.

To make this process more efficient, you can use a sander. We recommend using a sanding block for greater control. But if necessary, you can do it by hand. After sanding down the surface to the steel, it’s ready to paint.

Before you begin repainting your car, you'll need to prime it.

Spray paint primer on the exposed steel area, as this solution prepares the steel for a new paint coat. However, the first layer alone won't last.

As soon as you apply the first layer of primer, sand it back down. This process removes any rust particles that might have escaped the first time and will ensure that the steel is as smooth as possible.

Now, prime the surface again. If you want to be doubly sure that you get rid of all the corrosion, repeat the prime-sanding process again and again until you’re satisfied with the results.

It’s recommended that you sand your last layer of primer with 400-grit sandpaper for peak performance.

After sanding and priming the exposed steel surface, you can start painting the car. 

Apply the first layer of paint with a thin coat only. Once fully dry, use another piece of 400-grit sandpaper to smooth it down. By this point, you might have accidentally made a few thick spots in the paint layer, but that’s ok. You can use a sanding block for whittling them down over time.

Repeat the painting and sanding process twice more, for a total of three coats. After the third layer of paint is applied, soak another piece of 400-grit sandpaper with water and rub it over the newly painted area.

After all is said and done, you should have thoroughly removed any rust on the affected area and repainted the steel surface so that it’s completely smooth to the touch. Once you have achieved this result, you should apply a clear coat on top of the new paint to protect it from fading or minor scratches. Plus, getting to enjoy a glossy finish that’ll make your car look brand-new is the icing on the cake.

As you can see, fixing major rust on your vehicle is achievable, as long as you have the right tools for the job - and a little bit of patience. You don’t necessarily have to undergo heavy repairs to make your car look like it did before rust appeared. If you follow this guide, you’ll have the necessary skills to tackle any major rust removal jobs successfully.

Real insights from real owners

© 2022 J.D.Power. All rights reserved.

© 2019 J.D.Power. All rights reserved.