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How to repair car rust

Ellie Dyer-Brown, 1 year ago

3 min read

  • Advice
  • Repair
  • howto

WhoCanFixMyCar discusses how rust can affect your vehicle and the best rust treatment for cars

Particularly on older vehicles, rust can be a real problem - and not just for cosmetic reasons. In fact, rust is known as a silent killer; the longer you leave it, the worse it gets, until eventually the structure of the vehicle is no longer safe to drive.

The best rust treatment, in our opinion, is one that is carried out by a trained bodyshop specialist who can restore your car to a professional standard and prevent rust from coming back in the future.

Find out everything you need to know about rust and how to remove it in this guide.


What is rust?

Types of rust

What does rust look like?

Where does rust usually happen?

Can you paint over car rust?

Average cost to repair rust bubbles

How to prevent rust damage

Best rust treatment for cars UK

What is rust?

Rust is created when iron reacts with oxygen and water, resulting in an unsightly orange stain that begins to corrode the metal. This is known as iron oxide.

There are lots of different things that can cause cars to rust, some of which speed up the process considerably.

Age is one of the biggest factors. As the years go by, paintwork is subjected to wear and tear, eventually leading to the bodywork underneath becoming exposed. When this happens, the metal is vulnerable to rust because it comes into direct contact with moisture and air. 

Climate can also affect the speed at which your vehicle rusts. Living near the sea, for example, can make cars rust a lot faster than normal because there is salt in the air. Even the type of salt that’s used on roads can cause corrosion.

Types of rust

There are different types of rust, some being more severe than others. 

Penetrating rust is, as you might expect, the most damaging kind. If left untreated, it will eventually cause the corrosion of entire panels and parts that have to be replaced.

Scale rust happens when surface rust is left too long and begins corroding the metal. 

Surface rust, on the other hand, is the easiest to treat and the least damaging. It only affects the top layer of your car and usually happens in places where there have been bumps or scratches.

What does rust look like?

We all know that rust is usually brown or orange in colour, but there are other symptoms to look out for. 

Bubbles in the paintwork should be an immediate cause of concern; they indicate that air has got in between the paint and metal, and, as a result, it won’t be long until rust starts forming. 

Any scratches or dents, particularly where the paint has been damaged, are likely to develop rust. 

Finally, if you notice any puddles on the carpet inside your car - particularly in the boot or footwells - this could be a sign that the metal beneath has rusted. 

Where does rust usually happen?

Rust is easiest to spot when it’s on the outside of the vehicle, but you’d be mistaken in thinking that just because a car appears to be free from rust, it actually is. Sometimes rust begins inside a panel and spreads outward. 

If you’re worried about rust, always check your exhaust, suspension, wheel wells and frame rails, as these are the places where it’s most likely to form. 

Can you paint over car rust?

The answer, unfortunately, is that it depends. 

Light rust on the surface of the vehicle might be repaired with a paint job, but only if the correct procedure is followed; it isn’t as simple as just painting over the top of the rust to disguise it. 

Average cost to repair rust bubbles

The cost of repairing rust bubbles will depend on the extent of the problem; if they only cover a small area then this will be an easy job for a body repair shop and shouldn't be very expensive.

However, if rust bubbles are appearing all over your vehicle, the cost will be considerably more.

The best way to find out how much it will cost for a rust repair is to post a job on WhoCanFixMyCar. Reliable garages in your area will get back to you with quotes for the work that needs doing, allowing you to find the best price.

How to prevent rust damage

Maintaining your vehicle is an important part of rust proofing. Here are a few steps you can take to protect it from rust spots:

  • Keep your car as dry as possible.

    Of course, this can be a challenge thanks to the sheer amount of rain we see here in the UK, but something as simple as parking your car in a garage rather than on the street when you're not using it can have a positive impact.

  • Wash and dry.

    This is particularly important if you live near or travel to the seaside in your car regularly. When you get home, give your car a quick wash down with the hose pipe and dry it off with a chamois. This helps to prevent salty air from damaging parts of the car.

  • Use oil and wax.

    Wax adds an extra layer of protection to your car's body panels, and applying a squirt of WD40 will help to remove water from areas that are most susceptible to damage (and are usually hard to reach).

Best rust treatment for cars UK

Rust that only affects the surface of a car can be fixed at home if you have the time, patience and necessary tools. 

It's possible to buy a car rust repair kit online which will contain some kind of rust removal liquid, but most of the time you'll also have to purchase the tools you need separately.

If you're going to carry out the repair yourself, the best treatment is Hammerite Waxoyl. It's a powerful spray that not only gets rid of rust but also prevents it from coming back.

Here's how to fix rust on your car:

  • Remove the existing rust with an abrasive surface and a rust remover of your choice

  • Fill in the area with glass fibre repair gel

  • Sand the area

  • Fill in again as necessary

  • Apply a primer

  • Apply a base coat

  • Apply the desired colour

  • Finish off with a clear protective coating

If done incorrectly, the rust is likely to come back and continue spreading. 

That's why the best option is to find a car body repair shop where the rust can be repaired quickly and professionally, returning your vehicle to its original glory and preventing corrosion-related problems down the line. 

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