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Automotive Rustproofing Options To Keep Corrosion At Bay

Automotive Rustproofing Options To Keep Corrosion At Bay

Rust has been a problem since the first motorized carriages were built. True some of those early vehicles had wood frames and wood bodies, but there was still steel in the fasteners and brackets holding everything together. Some automakers turned to alternative materials that were less prone to rust. For example the DMC DeLorean had a stainless steel skin, the cold war era Trabant had a fiber reinforced plastic body, and GM’s Saturn division used injection molded plastic body panels. But more common automotive rustproofing methods involve protecting steel parts rather than replacing them with corrosion resistant materials. Here’s a few things to consider when researching car rustproofing.

First Line Of Defense

More than likely your vehicle has already been treated with some sort of automotive rustproofing from the factory. During assembly of a vehicle at the factory an entire chassis is dunked in a massive tank which contains a special liquid primer paint. The primer flows into all of the nooks and crannies where a paint sprayer would never hope to reach and is bonded to the metal using an electric charge. This is the base automotive rustproof paint that you don’t see underneath the shiny color and clearcoat. 

Rustproofing CoatingsHeavy- Duty Rubberized Undercoating, Permatex, 16 oz

Back in the dark ages of automotive history it was not uncommon for people to spray the underside of their vehicles with used motor oil. This was also back in a time when disposing of used motor oil meant dumping in a hole behind the house. Now we know that while this method of rustproofing cars can be slightly effective, it is terrible for the environment. Now there are better options for keeping corrosion at bay.

Rubberized Undercoating – This is probably what most people think of when you mention automotive rustproofing undercoating. Some may know it by the trademark name Body Schutz from 3M. These thick coatings are designed to protect metal from moisture and physical damage. They are typically a bit messy to apply.

Spray Coating – These products typically have a gel-type consistency that allows it to flow into crevices and even “heal” from minor scratches. They can be sprayed on using compressed air or from an aerosol can.

Should You Rustproof Your Car?

You may be wondering: is rustproofing a new car worth it? That depends on where you live and where you drive. Vehicles driven in areas where road salt and brine are a common addition to roadways during winter should have car rustproofing at the top of their list. Stopping corrosion from ever taking hold is crucial. For new vehicles you may be able to add in rustproofing to the price of the vehicle and have the service completed before taking delivery. For used vehicles consult your local NAPA Collision Center for potential rustproofing and undercoating options that best fit your situation.

When applying any sort of undercoating rustproofing keep in mind that most modern vehicles have a myriad of electrical connections, plastic lines, hoses, and wiring criss-crossing the underside. A fuel pressure sensor encased in rubberized undercoating will be a headache to remove, as would a fuel line connector. Be deliberate in application with consideration to any serviceable parts. Do not apply rustproofing coating to exhaust component unless it is specifically made for high temperatures.

The cost of rustproofing car, truck, or SUV will vary based on the type of coating you choose and how it is applied. There may be multiple preparation steps involved before any rustproofing is even applied, so take that into consideration. The area will need to be squeaky clean and dry for any coating to adhere correctly. Rust proofing car cost can also vary by the type of vehicle, but is typically a few hundred dollars.

Does Rustproofing A Car Work?

For the most part “yes” rustproofing a car does work. But there is a bit of routine maintenance involved. Whatever rustproof coating you choose needs to be inspected on at least an annual basis. These rustproof coatings rely on a tight seal to keep water from reaching the steel underneath. Things like scratches, scrapes, dings, and scuff can remove the rustproofing layer and expose the steel underneath. It is important to inspect the coating and repair any breaks in the protective layer immediately. If rust has already started to take hold, you will need to treat the corrosion first before applying a new layer of rustproof coating.

Check out all the body and chassis parts available on NAPAOnline or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on rustproofing paint or rustproofing undercoating automotive, chat with a knowledgeable expert at your local NAPA Auto Parts store.

Photo courtesy of Wikimedia Commons.

Brian Medford View All

With an automotive writing career spanning over two decades, Brian has a passion for sharing the automotive lifestyle. An avid DIYer he can usually be found working on one of his many project cars. His current collection includes a 1969 Olds Delta 88 convertible and a slant-6 powered 1975 Plymouth Duster.

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