Rust: What is car corrosion and how can you avoid it?

Car corrosion can be a big issue. Those who wish to sell a classic vehicle can encounter rust regularly, but even for newer cars, corrosion and its effects can plague the car-selling process.

The introduction of rust-resistant materials in newer cars has slowed the rate of corrosion, but it’s still essential for drivers of modern vehicles to take all precautions against it.

Estimations state that car corrosion can curtail a car’s value significantly. For example, too much rust can easily re-classify a vehicle from “complete and running” to “basket case”, leading to losses in sales value.

Thankfully, car corrosion is both preventable and treatable. If you want to prevent rust or learn about neutralising rust on cars, we have you covered below.

What is car corrosion?

Car corrosion happens when materials deteriorate because of oxidation. This process is usually caused by rusting, a chemical reaction that occurs when iron interacts with air and water.

Noticing rust doesn’t exactly mean corrosion is present. Rust is merely a type of corrosion. However, it is the most common sign that corrosion is happening; if rust is left untreated, damage can occur to your car’s engine, brakes and internal mechanisms.

Car corrosion: the risk factors

There are several risk factors for car corrosion:

Age - A car’s paintwork will peel away over time, which exposes the car’s chassis. These small exposures let water and air in, leading to rust. Salt and grit speed up the rusting process too, while very high temperatures also encourage it.
Materials - Old cars aren’t made out of the same rust-resistant materials as newer cars, leading to faster corrosion.
Climate - Countries with frequent rain, snow or high humidity have greater levels of rust as cars are exposed to more moisture.

Rust types

You also need to know the types of rust a car can have. Namely, there are three major rust types:

Surface-level rust - This impacts the car’s top layer, usually due to missing paint. This is the stage where rust should be treated.
Scale rust - This is the next stage of surface rust, where the rust starts to impact a car’s body panels.
Penetrating rust - This is when a car really starts to corrode. At this stage, rust completely cuts through body panels and impacts a car’s internal systems such as the engine, brake pads, etc.

How to prevent corrosion

Ideally, you want to prevent corrosion at the source before it occurs. There are a number of oils and waxes you can use to protect your car, but the most cost-effective method is proper storage and cleaning.

You should ensure your car is parked so it stays dry for as long as possible. Of course, this isn’t always possible unless you own a garage, especially in the UK! You can, however, ensure spare parts and nuts and bolts are kept dry.

Washing and drying your car regularly can reduce rust, too. You should still wash your car in the winter, especially if there is grit on the floor. Grit and salt speed up the rusting process, and cleaning your car can get rid of those pesky rusting agents.

Otherwise, there are anti-rust sprays you can purchase. For most cars, regular cleaning and drying should be enough to prevent surface-level rust from appearing.

How to remove surface rust from a car

So, you’ve taken care of your car, but you still see surface rust. Is it game over? Can you treat this yourself? Thankfully, with the right tools and a bit of elbow grease, you can get rid of surface rust for good. Learn how to treat surface rust on a car below.

Tools checklist

To start, you need:

Wax and grease remover
Microfiber cloth
Protective gear (gloves, mask and goggles)

How to remove rust from a car without sanding

There are ways to remove rust without sanding. Sanding can be difficult if you’ve never done it before, plus it’s possible to damage good paintwork in the process.

Two other tools you could use are citric acid and steel wool. For citric acid, add hot water and apply it to the surface area. Be sure to read all the safety information first and wear the recommended PPE.

Steel wool can remove rust, but it takes more effort than sandpaper. However, this extra effort comes with the added benefit of you being less likely to remove good paint.

If you have penetrating or scale rust, then you will need to get it professionally treated at a garage. You can only deal with surface-level rust at home. Of course, if you don’t feel confident about removing surface rust alone, opt for a garage.

Motoring tips and advice, here

Found a rust-free car? That’s step one. Now, you’ll need to make sure it’s ready for the road both mechanically, and on paper.

From knowing engine sizes to understanding motor finance products, our blog has the latest tips for keeping your wheels in shape. Keep us in your bookmarks and you’ll be on your way to becoming a motoring expert in no time.