How to Prevent Road Salt Rust & Damage on Your Car

  • January 24, 2021
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Given how harsh Canadian winters can get, drivers must brace themselves and their vehicles to face up to the impact of below zero temperatures and vast volumes of snow. Not only that, roads are guaranteed to be blanketed by heavy amounts of road salt, which is generally seen as a necessary evil to ensure everyone’s safety. We use the term ” necessary evil” to refer to road salt because while it helps pedestrians gain surer footing and keep vehicles from aquaplaning when the winter starts creating slippery roads, its composition is sure to wreak havoc on your car’s body and undercarriage.

Here, we talk about corrosion and road salt car damage and how to protect cars from rust due to salt exposure.

What Is Corrosion?

Corrosion happens when metal oxidizes after being exposed to moisture or water. More popularly called rust, it is a natural and slow process that gets worse over time with continued exposure and poor maintenance. In Canada, where the weather can go from being very hot and dry to icy and wet, cars and metal equipment are more prone to corroding than anywhere else. The automotive industry is extra aggressive when it comes to devising ways to fix and prevent rust formation.

The car industry is particularly vigilant against corrosion due to high atmospheric pollution levels and frequent exposure to de-icing salts come winter. The rate of rusting among land vehicles is about the same as those in marine settings.

For example, when a car goes over wet road environments frequently, mud and dirt can attach to exposed metals and create a longer time of wetness. This specific area will eventually degrade when the debris isn’t removed as soon as possible. In addition, de-icing salts, also known as road salts, contain sodium chloride, which has a strong rusting effect.

What Is Road Salt?

Road salt is an application of choice by many winter-laden communities because it can melt snow and help clear roads faster. Sodium chloride lowers water’s freezing point. This means that the more road salt is poured onto pathways and highways, the more difficult it becomes for water to turn to ice. However, there’s a catch to applying salt to roads. It works only when a little water is added to it, thus requiring the road crew to create a mixture of water and salt, called salt brine.

When heavy snowfall is expected, road crew usually pre-treat roads with brine to prevent ice from forming. If the surface is already covered in thick snow, salt brine works by seeping to the bottom and breaking the connection between the road itself and the ice. The ice and snow that’s left will then float on top of the brine so that it becomes much easier for cars passing through to break them up completely.

Why Does Salt Rust Cars?

While road salt helps make roads safer for vehicles and pedestrians, its effect on cars is the opposite. Salt chemically reacts with the metal portions of your car, or any exposed metal for that matter. Vehicle owners are mainly looking out for fuel and brake lines, as these are located closest to the undercarriage and are the most susceptible to rust and corrosion. Damage to either of these two can create considerable problems to your vehicle’s performance.

Oxidation does not affect pure iron that much, but since most cars use steel alloys for their formability, flexibility and tensile strength, this makes them more prone to rust. Alloys are created by adding a little carbon to iron to make them stronger and more ready for use on the road. However, this process is also what accelerates corrosion. Road salts speed up the exchange of molecules when exposed to steel alloy, making that particularly exposed area rust faster.

Tips on How To Protect Your Car From Salt

Knowing how to protect a car from rust can spell additional years of stellar performance from your vehicle. There are several ways to do this.

  1. Repair chips, scrapes, and rust spots before the winter season starts, to limit exposure to salts.
  2. When autumn comes, take it as an opportunity to conduct preventive maintenance on your car. Give it a thorough washing from top to bottom, and then coat it with wax. Doing so will help stop salts from adhering to the surface and eventually causing rust. Don’t just wax once and then hope for the best. You should regularly reapply the product during the winter season to ensure that your car is well-coated throughout.
  3. Wash your car regularly and extra aggressively, paying close attention to the corners, crevices, and the entire undercarriage. Do this at least once every week if you live in an area that experiences very snowy weather.
  4. If you have an old car, then give it extra love and attention. Dated vehicles are especially susceptible to rust formation after being exposed to salts for many years. It is highly recommended that you seal the undercarriage totally to deflect the salts and stop them from sticking to your body. You can apply this in the comfort of your garage, or you can seek a professional’s assistance to ensure that the task is done the right way.
  5. While you can’t prevent salt corrosion on cars, especially in Canada, you can limit buildup. The simplest way is to avoid areas that will have you driving through deep snow. Another site to avoid is large puddles, as salt tends to collect in large amounts there.

How To Fix Rust Spots Caused by Road Salt

Corrosion happens in phases, so fixing rust spots starts by knowing which stage of decomposition the area is in.

If it’s surface rust, which typically shows up in the form of cracks, scratches, and paint nicks, it will be quite an easy fix. Like a paint repair job, you can use sandpaper or an abrasive wheel to cut through the problem area until the metal becomes visible. You can then apply a layer or several of rust inhibitor to stop its progression. Leave it to dry totally for 24 hours before closing it up with primer, paint, and clear coat.

If it’s scale rust, you start with using a wire brush and a grinding wheel to get rid of the rough scale and then smoothing it out with sandpaper. Do this until you reach the bare metal and there are no more rust flakes left, and then use a sealer or filler to close it back up. Ensure the area around it is roughed up amply so that the sealants, which come next in the process, adhere to it. You can then apply a rust converter and restore the area as usual.

If it’s penetrating rust, which means there are now visible holes on the body, then body filler will not be on y our side. Better yet, do not attempt to fix this patch yourself, especially if the rest of your car’s structure has also become problematic. It’s best to approach a professional or a certified repair facility to get the job done.