Most modern vehicles do not show visible signs of rusting until they are over five or six years old. Beyond that, in the high salt environments of central and eastern Canada, the vehicle will experience mechanical and body deterioration due to corrosion. By the seventh or eighth year in service, this deterioration will usually result in increased maintenance and repair costs, or a reduced market value for the vehicle upon resale. Repairs could include lower body panels like door bottoms and fenders, and mechanical parts like metal gas tanks, electrical connections, and brake, fuel and air conditioner lines. Unfortunately, most dealer-applied rustproofing leaves a lot to be desired. It’s usually a one-time only application of a product that dries out and cracks as the vehicle gets older. A CAA study undertaken in the 1980s revealed that 85% of dealer-applied rustproofing left one or more high-risk areas of the vehicle unprotected.

The APA has approved the following rustproofing treatments:


Antirouille Barry
5005 Buchan, Montreal
Tel. 514-344-1168

A small shop recommended by the APA for over 25 years. One-time grease application includes the inside of the floor in the front passenger area underneath the carpet. No holes are drilled. Barry’s crew removes trim panels if necessary. Cost for a complete treatment: $450-$750 depending on the vehicle; $275 for the initial base treatment (undercarriage only); $25 off the initial base treatment for APA members. After three years, retouching is recommended and costs $120-$150 depending on the vehicle.

Across Canada

Krown Rust Control
Tel. 1-800-267-5744

Annual rustproofing. The product is an excellent penetrant. It outperformed similar competing products in ASTM durability tests {ASTMB-117}, and is used by the military and large commercial fleets. Krown recertifies technicians annually to maintain quality and provides excellent support from the head office. The application is thorough, with holes drilled using special bits to minimize damage. Most competitors cover about 10 areas on the vehicle; Krown does over 25. The cost is $145-$175 per year depending on the vehicle, and resprays are guaranteed against price increases for as long as you own your vehicle. APA members receive a $5 discount off the current regular retail price of a Krown application. The Krown warranty covers seam or crevice corrosion, and is honoured across Canada.

Should I buy rustproofing?

This depends on the length of time you keep the vehicle. For example, if you lease a new vehicle there is no advantage to rustproofing. If you intend to keep the vehicle for a period beyond the manufacturer’s rust warranty, you should consider rustproofing. Do not purchase rustproofing from a dealer. APA recommends Krown Rust Control. Please note: Most car dealers do not recommend Krown. Often scare tactics are employed by the dealer in order to sell their own rustproofing. Sometimes dealers erroneously claim that drilling holes will void the manufacturer’s warranty. This is misleading, and drilling holes may be necessary in order to ensure that the the product reaches the seams, cracks, crevices, etc. where rust really begins.

Most dealers use a wax-based anti-rust spray. Wax is not a “self-healing” product. This means that when you have stones and rocks hit the underbody, they will actually chip away the wax. Also, over time the wax hardens and cracks and moisture will get trapped into these cracks and crevices, increasing the probability of corrosion. One of the best rustproofers is Krown (, a petroleum-based spray you should do every year. Doing Krown every year is more expensive in the long run, but you get what you pay for. If you do not plan on keeping the car more than 4 yrs, then don’t bother with any rustproofing. If you do not rustproof your car, rust begins to form in hidden areas of the body panels during the first year, invisible without taking apart door panels and trim for a look. When rust appears 6 or 7 years later, the damage actually began years ago. 90% of rust damage on vehicles begins inside-out.

When dealers offer a “lifetime” or “10 year” rust warranty, it’s usually a very-well-hedged bet on their part. Profits are large on the initial application; total cost to the dealer is about $150 and the treatment is usually sold from $499 up to $795. Claims rarely succeed because the warranty will have been voided by the time rust becomes obvious, for one of a variety of possible reasons. First off, you may have to bring your vehicle back every year for an inspection and the dealership may ask you to pay for “touchups”. If you miss just one annual inspection, the dealer may void your rust warranty. Some warranties cover only a “perforation” so you may have to let the vehicle rust through before collecting and run the risk of the rustproofing company refusing the claim because of “neglect!” Some rustproofing warranties cover only defects in the product, but not its application; if the dealer missed a vulnerable area, the warranty company won’t cover eventual corrosion damage to that area. Krown charges the full amount to respray the entire vehicle, minimizing the possibility of missing an unprotected area year-after-year; this is more likely when a dealer performs only the initial application and an annual visual inspection. And some rustproofing warranties are not transferable if you sell the vehicle. It’s no wonder then that dealers are happy to sell you lucrative rustproofing packages when the possibility of a successful warranty claim is unlikely.

Have questions about Electronic Rustproofing Modules? Read these related articles:

The Globe and Mail: Do I need to install an electronic rust inhibitor?

AutoTrader: Goof of the Month: Rust Protection isn’t Magic

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