Rust is quite possibly the most common enemy of cars and trucks. It is the inevitable interaction between iron, water, and oxygen. For those of us living in Ontario, we have seen firsthand the amount of salt used on the roads in the winter and how it builds up over time on our cars through the winter months.  Rust assured, we’ve looked into this for you! Rustproofing your car is the best way to defend it from any corrosive contaminants that you aren’t able to easily wash off. In this article, we discuss what rustproofing is, how to spot rust on your vehicle, as well as the best ways to keep rust from attacking your ride.

What is rust and where does it come from?

As mentioned above, rust is caused by the interaction of iron (vehicle), oxygen, and water (weather, washing). It can occur anywhere on the body of a car. In fact, surface rust is often the tip of the iceberg, as it’s common for oxidization to form inside a panel or part of your vehicle, and work its way outward. The most important thing to look out for is any exterior paint-bubbling. This is often an early sign of rust.

Where does rust typically occur?

Rust, or iron oxide, can occur anywhere. It forms when metal is exposed to moisture and oxygen for an extended period of time. The addition of salt, climate, and poor car maintenance also all play a role in creating rust on vehicles.

There are three main types of rust on cars:

  • Surface: Can form on the top layer of paint near scratches and nicks.
  • Scale: If surface rust is not taken care of, scale rust will appear, which can corrode body panels and remove paint. This will leave bare metal exposed to the elements.
  • Penetrating: If scale rust goes untreated, you’ll begin to notice penetrating rust that will comprise the structural integrity of your vehicle.

Where to look for it

According to experts, you need to be diligent and observe both underneath, as well as around, your vehicle:

Underneath your car

  • Frame rails: Runs underneath both sides of your car and underneath the doors.
  • Wheel wells: The curves above your tires are prone to rusting, especially in older cars that typically don’t have arch liners.
  • Exhausts: Your tailpipe is exposed to moisture from the inside and outside of the car, which can be trapped by mud and dirt.
  • Suspension: Its proximity to tires can flick up dirt and other elements on the underside of the car, causing rust.

Around your car

  • Floor of the trunk: Pull up any carpet to look for any signs of rust.
  • Windscreen: Areas around glass are prone to leaking.
  • Doors: Be sure to check your doors, inside and out.

Bubbling under the paint usually indicates that paint has lost contact with the panel underneath because water and air have gathered in between. It won’t be long before the area is covered in rust.

Also watch out for

  • Puddles: Dampness or water damage on the carpet, the floor or the trunk is an indication that the metal underneath has rusted.
  • Body damage: Nicks and dents in the frame often lead to rust when left unattended.
  • Irregular paint: Spots and strips of paint that don’t match the original paintwork could be the work of a rust repair job. It may come back if not properly repaired or sealed.

What is rustproofing?

Rustproofing your car is the process of preventing rust through the application of specific chemical compounds. Protection against rust and corrosion is achieved by applying a barrier between the vehicle’s body and any external elements. Depending on the type, it can be used all over your car or only on the underside.

According to Statistics Canada, Canadian roads endure about five million tons of salt annually to melt ice and snow during the long winters. These corrosive de-icing chemicals also happen to be terrific at eating into the rust-resistant alloys in modern cars.

Reasons to rustproof your vehicle

Rustproofing your car in Canada is more than just aesthetics. Damage from rust to your vehicle may compromise mechanical and electrical parts, leading to ensuing failure. If the potential cost of rustproofing has you hesitating, keep these points in mind:

  • Longer life: Your car will last longer, putting off need to replace it sooner.
  • Lower repair costs: Rust control products can prevent moving parts from seizing up, lessening the damage to your electrical system.
  • Trade-in value: Rustproofing is a big selling factor that can boost your car’s resale value.

Consumer watchdog, Automobile Protection Association, suggests that drivers can expect rust after five or six years of ownership.

What is the best rust protection for a car?

Rustproofing treatments come in many forms. According to, there are three different treatment options that are available:

1. Most expensive: Grease-based treatment

A grease-based treatment should be performed during the first year of ownership. Fortunately, this treatment will last for the entire lifetime of your car. Some touch-ups may be required after five or six years in order to maintain complete protection. This treatment can be done directly by the dealership or in a specialized workshop.

2. Most common: Good oil treatment

A conventional oil treatment is the most common type of rustproofing and is relatively inexpensive. However, it must be done, ideally, every year. Holes are drilled into the framework to allow the technician to access areas of the car where salt and calcium accumulate. Most rustproofing technicians will also seal the holes with plastic caps.

3. Alternative methods: Electronic rust protection

Several other “alternative” rustproofing techniques, such as electronic rust protection, are also an option. An electrical current is used to prohibit rust from forming. However, your vehicle is made from a variety of materials, such as plastics, rubber, and aluminum, which do not conduct the current the same way. This makes this treatment ineffective and drains current from your car battery.

What is the difference between rustproofing and undercoating?

Most cars will leave the factory with some kind of hardened undercoating applied to the undercarriage. This is applied long before the vehicle is outdoors. It can potentially chip or crack from wear over time. Also, contaminants can be sealed in between the coating and the undercarriage when first applied, trapping contaminants that can cause rust. The rubberized coating is also flexible, which allows contaminants to squeeze in if a rock chips the coating. Therefore, you are probably better off leaving your undercarriage uncoated and simply rinsing it off as often as you can throughout the winter.

How long does rustproofing last?

Rustproofing is not a one-time, permanent solution. You should have your car rustproofed consistently every year. Experts recommend spraying it before every winter and again in the spring to neutralize any leftover salt. This is something you need to stay on top of in order to avoid rust.

Is rust damage covered by insurance?

No. Rust is a type of normal wear and tear on a vehicle, therefore rust and corrosion is not covered on a standard policy. Rust is expected to happen to cars, so many insurers will not approve the claim. However, if you have comprehensive insurance coverage, you can be covered for rust if an improper repair job done on your car results in corrosion, or if the vehicle is damaged by flood or heavy rain. However, you’ll have to prove that the rust happened due to faulty repair or extreme weather.

How much does rustproofing your car cost?

Prices are usually governed by the size of the vehicle. Cars will cost between $120 to $150 to rustproof. If you are rustproofing a minivan or SUV, the costs will range between $130 and upwards to $170.

4 tips to prevent rust on a car

Here are four easy tips to help you limit rust on your automobile:

  1. Wash and wax your car.
  2. Touch-up any chips or scrapes.
  3. Purchase an aluminum-based car, which are less prone to rust.
  4. Park your car indoors or away from rain, trees or flooding areas to minimize rust.

So, is rustproofing your car worth it?

To decide whether or not rustproofing is worth the expense for your vehicle comes down to usage:

  • If you are a snowbird and have your vehicle protected in storage during the long winter months, then you probably don’t need to rustproof your new car.  Be sure to speak to one of our isure brokers about parking insurance for your vehicle while you are away.
  • If you are leasing your car or intend to sell it in a few years, your vehicle is unlikely to encounter rust. As long as you wash your car regularly, the expense of rustproofing is unlikely to create any value for you. So, you can skip it.
  • If you are interested in long-term ownership, rustproofing will provide real value. Whether you live in the city or the outskirts, you can protect your vehicle for the long run. For added savings, ask one of our isure representatives about an OPCF 43 – Waiver of Depreciation endorsement for your new vehicle. Your insurance company will not deduct the depreciation of your vehicle for two to three years.

Rustproofing your car is a great way to protect your investment if you plan to keep your car for more than a couple of years. If you can prevent or even slow down the rusting process, it might just mean that you can keep your beloved vehicle around a little while longer.

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