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By John Fossen, FCN

Chicago-area Ford dealer John Guido remembers a time when at least one out of every two vehicles sold at his Arlington Heights Ford store was rustproofed by the dealership.

"Rustproofing was a big after-sale item, said Guido. "You did it either just underneath the car or you did complete rustproofing, where you went into the door jambs, quarterpanels and other areas. The complete treatment cost about $295."

However, as automakers improved corrosion protection, Guido and other dealers began to experience a decline in rustproofing business.

"By the late 1980s, the amount of rustproofing we did began to slow noticeably," said Guido. "I don't do it at all now. I haven't for years."

Lindsay Fraenkell, a 26-year-employee at a Ziebart-Speedy Auto Glass store in Minneapolis, has a similar story.

"We only do about 20 percent of the rustproofing that we did in the early 1980s," noted Fraenkell. "We've had to diversify and offer additional services."

That's because rust is practically a non-issue on modern vehicles, thanks in part to Ford Motor Company.

One of the first major automotive corrosion protection innovations – a special paint layer called anodic electrocoat – was introduced by Ford in the 1960s. Also known as "e-coat", this electrically charged coating was applied in a large tank to an unpainted steel body. Ford highlighted the new process in a print ad that appeared in a 1969 issue of Life magazine.

In the late 1970s, cathodic electrocoat began replacing anodic electrocoat. The newer coating offered improved corrosion protection and reduced the amount of energy needed to apply it. Not only was Ford quick to make the switch, it also became the first automaker to convert all of its North American assembly plants to lead-free cathodic electrocoat by the mid-80s to reduce the environmental impact of lead-containing materials.

Advances in steel added to improved corrosion protection for customers. One-sided galvanized steel, which contained a protective layer of zinc, led to two-sided galvanized steel. The inclusion of dip phosphate by Ford in the 1990s further enhanced rust resistance. Prior to dipping, vehicles were sprayed with phosphate. Spraying provided cleaning and conditioning to the outside of the steel body, but not to the inside where corrosion from road salt frequently begins.

To help ensure effective application of the company's present corrosion protection system, Ford relies on sophisticated computer models in a process called "digital preassembly."

"We do early computer-aided design work in which we take a vehicle structure as it evolves and evaluate it as an analytical computer model," explained Jeffrey Helms, manager, Materials Development and Release, Ford Global Paint Engineering. "This allows us to predict and address such things as electrocoat coverage, voids and drainage issues before we physically run a vehicle through the actual electrocoat system in the plant."

Helms says that Ford also uses computer-aided engineering tools to develop and tune the large ovens that heat and cure the electrocoat. These tools are especially effective in helping Ford meet the challenge of curing e-coat on thicker metal panels, which are required to comply with more stringent safety regulations.

As added corrosion protection against stone- or gravel-related paint chips, polyurethanes and polyvinyl chloride coatings are employed underneath the paint on rocker panels and other lower body areas. Body fasteners, such as bolts and screws, also are treated with special anti-corrosion materials.

Ford engineers continue to look for innovative ways to improve corrosion resistance while protecting the environment, according to Ford Corrosion Technical Specialist Jeff Richardson.

"For example, the company is studying a new dip pretreatment process that requires less energy and water, eliminates process waste and further improves the corrosion resistance of metals used in vehicle construction," he said.