All About Rust

What is rust?
Rust is the substance that is formed when iron begins returning to its natural state (iron ore) by combining with oxygen to become ferric oxide. This chemical combination of metal and oxygen is called oxidation. The oxidation of any metal generates corrosion, and the corrosion of iron specifically is what we commonly call rust. The steel from which cars are made is iron alloyed with a small amount of carbon and therefore may rust. Wherever iron or steel is exposed to air (oxygen), rust is likely to occur eventually. The oxidation process is accelerated by moisture, acid rain, salt and dirt, all of which act as catalysts to speed up the rust process.

Do today's cars still rust?
Yes. Rust can begin in any area of the body, inside or out, that is exposed to the elements. A recent study conducted by Ziebart International Corp. involving 240 vehicles manufactured in the 1990s determined that 105 of the vehicles (44%) showed signs that rust had formed on the inside of metal panels. The predominant locations were the bottom seams on doors, the front seam on hoods, the lower seam on trunk lids, radiator support frames, fender attachment points and gasoline filler door areas. Current model vehicles have the same construction as the vehicles studied.

Auto makers protect the outer surfaces of fenders, doors and other metal parts with coatings of paint. Even though inner surfaces, such as door panels or the side of a fender that faces the chassis are coated, it is a much more difficult task to protect those surfaces from rust. Rust may begin on the inner side of the metal that is hidden from view and work all the way through the metal to the outside, painted surface, where it bubbles-up and forms a hole in the steel panel. Rust can begin in any area of the body that is exposed to the elements.

Doors tend to rust at the bottom seam because water, dirt and other corrosive substances fall into the door through the window slot. If drain holes at the bottom of the door become plugged up, corrosives accumulate and rust begins. Rocker panels-which form the metal "step" under the door are subject to rusting because they are at the lowest point in the car body shell and may accumulate moisture, salt and dirt. Any place on the vehicle where two pieces of metal are joined is a likely place to detect rust. These joints hold moisture, salt, dirt and other corrosive particles that promote rust. The fender support braces are one primary area of this type. Also, rust can form where paint chips off the outer surface of a vehicle. The front edges of hoods and trunks are common places for rust to appear because they are the most likely areas of a vehicle to suffer paint damage and because water that falls on the vehicle runs down to the edges of the hood and trunk.

Doesn't the manufacturer's guarantee on my car cover rust damage?
Most guarantees limit the amount of time they cover rust damage and usually exclude coverage of rust caused by such environmental factors as stone chips and floods. For example in the Philippines, the corrosion warranty for a popular Japanese manufacturer states that what is not covered are, "Factors beyond the manufacturer's Control… Damages and/or surface corrosion problems due to the environment such as acid rain, airborne fall-out, salt, hail, windstorms, lightning, floods, other acts of God and the like are not covered". For a different Japanese manufacturer, their warranty excludes "Damage or failure resulting from stone chipping, chemical fallout, tree sap, salt, hail, floods, windstorm, lightning or other environmental conditions". Another car manufacturer's warranty covers corrosion that causes perforation (rust through) within three years, but if the corrosion does not create a hole (i.e. perforation)-and is not caused by surface paint damage due to corrosive substances, industrial fall out, acid rain, chipped paint, scratches and the like - there is no coverage. You should review your car's warranty guide carefully to determine the extent of corrosion coverage.

How can I protect my car against rust?
Aftermarket rust protection coats the inside surfaces of metal panels to protect them from moisture and other corrosives, preventing rust from starting. This effectively seals out oxygen (air) and H2O (water) from contact with the metal. It's important to rust-protect your vehicle before rust begins.

Look for a process that uses a durable, long-lasting protectant, supported by periodic maintenance; and ensure that the rust-proofing is applied by professional, well-trained technicians.

Wash your car regularly as recommended in your owner's manual, including the underbody, to remove corrosive substances; and clear the drain holes at the bottom of doors and under rocker panels. Spot check and power clean areas of your car that are susceptible to rust to be sure that water, salt, mud, dust-control chemicals and other corrosives are not collecting there.

For used cars which may already have began to rust, Ziebart offers used car rust-protection which first treats your vehicle body shell with its Rust Eliminator chemical before proceeding with the Rust-Protection process.

Does aftermarket rustproofing void the manufacturer's guarantee on my car?
No. The overall manufacturer's warranty is not jeopardized by rust protection, but manufacturers will not honor any sheet-metal claims resulting from a faulty application of rust protection. Sheet-metal claims do not pertain to any mechanical or non-corrosion claims. Fortunately, Ziebart provides a lifetime guarantee for any rust damage, and the terms of the guarantee far exceed the terms offered by manufacturers.

What guidelines should I follow to determine if my car needs after-market rustproofing?
Every car can benefit from after-market rust protection in two primary ways:


a. The physical appearance and performance of the vehicle are preserved. 
b. Its resale value is increased.

If you have a car plan from your company, remember that you may want to purchase it at the end of the plan's term. So whether you have a car plan or own your vehicle outright, you should have it rust-protected if you plan to keep it for more than two or three years. 


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