If you’ve ever tried to restore a vintage, classic or antique car, you likely noticed patches of rust on these older models. You might also wonder why vehicles from the 1990s on don’t display as much damage.
Just as car manufacturers have incorporated more computer systems into vehicles, they’ve also focused on improving corrosion resistance for the body and its parts.
As such, newer models are more likely to be made of galvanized steel, treated to reduce rust and have aluminum components. Here’s what you should know.
Galvanized Steel
Starting in the 1980s, more car manufacturers started using galvanized steel, an alloy bonding steel to zinc. Although you’ll still find cars made without galvanized steel in other markets, American models use this material for the body and panels by default.
Through this bond, pure zinc is on the exterior, with zinc in the layer between, chemically attached to the iron composing the steel. In ideal conditions, galvanized steel can last up to 70 years without corroding and, for this reason, it’s commonly used for OEM parts.
In spite of these benefits, galvanized steel is not perfect, nor can you expect to leave your car unattended in the elements without damage. Instead, any place the steel has bent or welded is more susceptible to rusting. To address this, some car manufacturers will add a sealant for extra rust protection in these spots.
Whether used for the body or parts, what’s so special about zinc? For one thing, zinc is not applied as a coating that will come off like paint. Rather, it forms an electrolytic bond with the iron in the steel. Because the zinc is on the steel’s surface in a thin layer, it comes in direct contact with the oxygen in the air, ultimately protecting the alloy underneath and greatly reducing the risk of corrosion.
However, the zinc layer wears away with time and the steel will be exposed. In parts of the country with more water or where salt is used on the roads, the corrosion process is sped up, leading to premature rusting if you don’t take care of your vehicle.
Aluminum Parts
Aluminum has a reputation for being corrosion-resistant. For this reason, car manufacturers and companies who create aftermarket parts have started using it more. It is lighter than steel and may even improve a car’s gas mileage. Unlike galvanized steel, aluminum can be contaminated easily and its lighter construction may make it more prone to damage.
Unfortunately, for a few years in the 2000s and 2010s, car manufacturers were touting aluminum as corrosion-proof. Consumer Reports disproved this notion in 2015, finding that aluminum may experience premature corrosion. In response, Ford has faced a class action lawsuit for making this claim about their F-150 and Explorer models.
Other Changes
Additional design issues help combat corrosion. The undercarriage is often the first spot rust forms, so this area may receive an undercoating for complete, all-around protection.
More recent developments reduce spots where mud can gather and today’s vehicles use fewer seams, as these also tend to be some of the first spots corrosion forms. In other cases, plastic may replace metal in rust-prone areas.
Added to this, manufacturers are careful with the metals used for the exterior. Even for trim, galvanized steel is preferred over stainless steel and anything chrome-plated.
If you notice spots of corrosion or flaking paint on your car, reach out to DaSilva’s Auto Body for rust removal services. To learn more about our services or schedule an appointment, contact our Naugatuck shop today.
