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How to protect your car against road salt and prevent rust

Road salt can have damaging irreversible effects on your cars interior and exterior.

Here are some tips to help prevent rusting caused by harsh road salt:

In the midst of another harsh Canadian winter, drivers should consider protecting their vehicles to endure the copious amounts of road salt that’s spread on our roads. Ice melter is a necessary evil – for safe driving and staying sure-footed on sidewalks and driveways. This guide will help you prepare your vehicle and driveway to survive winter and maintain good looks and durability for years to come.

For most people, a car is big purchase so it’s worth maintaining to ensure reliability, appearance and performance during your years of ownership. The average Canadian owns a passenger vehicle for 5-6 years so unless you intend to drive a car until it’s time for the scrap yard, you need to consider its resale value. The greatest factor contributing to resale value is appearance so any sign of rust will have a negative impact.

How to protect the exterior of your car from rust:

The best way to protect your car against road salt that causes rust is to have the body oiled annually with a rust proofing spray. There are automotive shops like Rust Check who specialize in rust proofing.

Rust forms when water and air combine to form a crust on your vehicle. Road salt acts as an accelerator for corrosion. Most people think that fall is the best time of year to have a car’s body oiled, however spring is the optimum time for the application – when moisture levels fluctuate. That’s when vehicles are most prone to rusting.

The most effective rust proofing product is a light mineral based oil that will creep into door seams, folds, joints and weld spots where rust often starts. Oil based sprays displace moisture and can be applied to a wet surface. This, combined with a thicker gel type oil for the underbody, wheel wells and rocker panels, will provide optimum protection against road salt. Rust proofing oil also protects your electrical components, brake and fuel lines against corrosion. Road salt will not damage your winter tires, nor will this oil application.

There are automotive shops like Rust Check who specialize in rust proofing. For the past ten years I’ve had my cars treated annually by Kelly’s Rust Check and as a result, my cars have never shown any sign of rust. Rust Check’s best “Coat and Protect” application (combination of light oil and gel) costs $130 for cars and $150 for trucks/SUVs. Contrary to some owners’ manuals, it will not void the manufacturers warranty. The thicker gel hardly drips but parking on the street for a day is still recommended. The oil won’t harm the driveway but will stain it for a month or so.

Other anti-rust options:

Sealants are a “one time” rust inhibiting application that contains tar, wax or polymers. Sealants provide a protective barrier against the elements (like road salt) but unlike light oil sprays, sealants do not creep as deep into a car’s metal folds where rust typically begins. Sealant treatments are commonly sold through car dealerships, and to be effective, must be

applied when the vehicle is clean and dry. There is a higher upfront cost compared to oil sprays and the sealant application requires an annual inspection and possible touch-up (often an additional cost) to maintain it’s warranty.

Electronic rust inhibitors are another anti-rust option typically sold by auto dealers. They are expensive and not as effective as oil sprays. Although it has been shown that electronic rust inhibitors work well on bridges and boats, their effectiveness on vehicles has not been proven over time.

To keep your car looking it’s best, stay on top of fixing paint chips and scratches with touch up paint, available at OEM dealerships and auto supply stores. Exposed metal will form surface rust, then blister, turning into a serious rust problem if not quickly dealt with. If surface rust has formed, use a can of Rust Check oil to spray the area and slow the rust from spreading.

New cars can start to show signs of rust in just 2-3 years if not treated with a rust inhibitor. It’s worth the few hundred dollars a year to be diligent and take this added measure of insurance to maintain your vehicle’s appearance and resale/trade-in value.

Protecting your car’s interior against road salt:

Rubber car mats are a must to protect your car’s interior against the elements of winter. Slush containing harsh road salt will melt off your boots and stain your interior carpet. It is difficult to scrub out the stains and road salt will eventually rot out floorboards.

The best winter floor mats are made of rubber and custom fit with high sidewalls. Buying rubber mats from an OEM dealership can be quite expensive. Aftermarket custom fit mats like WeatherTech are another option and usually cost less than OEM. Generic fit mats keep the bulk of the slush off your carpet but do not cover the corner spots. They are much cheaper than custom fit mats but do not provide maximum coverage.

Road salt and alternatives:

Protect your driveway against harsh road salt and ice melters:

Even if you don’t salt your driveway for sure-footed safety, road salt will drip off your car and deteriorate, crack and stain the parking surface. Protect your driveway against road salt by applying a commercial grade sealer (petroleum and oil base) like Black Mac for asphalt driveways and high gloss clear sealer for concrete and interlocking brick. These products will create a barrier on your driveway surface and reduce the harmful effects of ice melter. Treat your driveway once a year to maintain optimum appearance and longevity.

Doctors tell us to moderate our salt intake. The same advice goes for spreading ice melter salt on your driveway and walkways. Read the disclaimer on the bag of ice melter and you’ll see what I mean.

The most efficient type of ice melting salt contains calcium chloride (CaCl) as it works at lower temperatures and with less product required compared to rock salt containing sodium chloride (NaCl). Both types are readily available at retailers (until the next big ice storm). Calcium chloride ice melter is more expensive than rock salt, however less is required to be effective. Municipalities primarily use rock salt on our roads because it is the most cost efficient for the volume required to keep roads safe for driving over the course of winter.

Nothing works as well to melt ice as salt. Sand provides traction but does not melt ice. More environmentally friendly options like potassium chloride (potash), urea and beat juice are far more expensive than rock salt and less effective. Heated driveways provide the luxury of not needing ice melter but this is obviously a very expensive undertaking.

Regardless of what methods you choose for protecting your car and driveway against harsh road salt, be proactive and prepared. A lot of Canadians dread winter. The appearance of rust on our cars and driveway cracks is evidence that winter takes a toll on us all. However taking the above measures to protect your car and driveway against road salt will help make winter more bearable.

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