Preventing corrosion: does road salt damage the car? – How to remove rust

There were times when road salt was pretty damaging to car paints. Fortunately, these times are largely over. Modern paints are now relatively resistant to brine. However, this resistance has its limits.

De-icing salt is the colloquial term for de-icing salt, which is used in the context of local winter services to clear snow and ice of roads faster. For environmental reasons, the use is regulated by various regulations and is prohibited in most municipalities for private individuals. Nevertheless, it is always found on public roads and concerns about possible damage to vehicles persist.

How harmful is road salt to cars?

As soon as salt and moisture come together, the salt develops a caustic property that poses a danger to the surface, the underbody and the brake lines of vehicles. The underbody is particularly exposed to this risk if the salt has been rubbed onto the body. In this case, the crystals can act like sandpaper. When it comes to paint, the point of attack is usually different, because road salt residues can do relatively little damage to intact car paint. However, the situation becomes more difficult if the car has already been damaged, for example by falling rocks or hail. Should salt penetrate in such places, the stain can spread slowly and cause rust.

How can you protect the car from damage caused by road salt?

If you want to prevent littering, you have to cultivate a good washing routine. If road salt residues and other winter dirt get stuck on the car, a visit to the car wash is recommended at least once a month. But before you get started, you should first remove salt grains and granulate residues manually. Otherwise they could erode the paint surface.

Although underbody washing is always advisable, it can be problematic when the temperature is below freezing if water is frozen in the pipes or cables. In this respect, it may only take place in spring or autumn.

Furthermore, when avoiding paint damage to the car, it is still important that you check the places after washing the car where paint damage typically occurs. These include, for example, the bonnet, the wheel arches and the exterior mirrors.

Protect the paint with wax

You can make your car winter-proof by preserving it with a wax beforehand. This is the only way to reject dirt particles. The best way to do this is to polish the car by hand. This method is not only used to make scratches easier to repair; it is also the only way to protect all areas on the car. The wax layer has to be renewed at regular intervals. As soon as the so-called pearl effect wears off – when water flows on the surface like a pearl – it is time for a new layer. Depending on the quality of the product, the wax offers protection for between six and eight weeks. As a rule, it is sufficient to carry out washing by hand twice a year. In between, you can easily use the washing program in the car wash.

Who pays for road salt damage?

Unfortunately, the paint protection of your car is your own responsibility. The municipality is not liable if you suffer damage to your car’s paintwork from the scattering of salt. Your car insurance also expects you to take care of the underbody protection on your car yourself, which is why it does not cover any costs in the event of damage. This applies both when road salt attacks the seal and when your rims weaken due to road salt. This means that you are usually dependent on protective measures such as the use of rim spray. Such tools are usually enough in parallel with the above-mentioned precautions to avoid damage.

How can you remove rust from the car?

Despite your efforts, there may still be rust on your car after winter. The good news is that you don’t have to go to the workshop with the slightest sign of rust. You can remove some rust yourself.

See the first signs of rust

The first sign is often the appearance of rust film. Fortunately, rust can be removed by simply wiping the area with a rag or normal car polish.

Remove light rust with acid

If the rust is already attached to the paint, we recommend using a rust remover for the car. For example, you can use a dilute phosphoric acid. Otherwise, so-called rust converters from the hardware store are suitable alternatives. These convert the rust into an iron compound, so that the porous structure changes and further erosion is prevented. However, the treated surface will not shine again – instead, a dark gray stain typically remains. The rust can no longer spread, you will need a new coat of paint afterwards. In this case, you should consult an expert.

Remove stubborn rust

In some cases it may be advisable to rub the rust away with sandpaper or a wire brush. Deep spots may need to be refined with a grinder. Make sure that the rust is completely removed or until the metal shines through slightly. If there is deeper corrosion, you would have to apply a special rust remover.


As a rule, road salt is not a threat to your paint job. Most cars are already protected in winter by the ingredients in the paint. However, if your paint has scratches or similar weak points, this could lead to rust problems. In general, however, you can protect yourself well by having your car washed regularly in winter. In addition to freezing temperatures, you should also frequently remove salt grains and granulate residues.

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