Tesla Cybertrucks Are Rusting Despite Being Stainless Steel: Here’s Why

The Tesla Cybertruck isn’t the first vehicle to feature all stainless steel body panels. That distinction belongs to the DeLorean, manufactured in Belfast between 1981 and 1983 and featured in the “Back to the Future” movie trilogy. My adopted nephew, who works at the Tesla production facility in Fremont, California, provided this fun fact when I consulted him about reports that the stainless steel body can rust.

He dismissed these reports with a chuckle, explaining that they are due to something called “rust dust.” By way of explanation, he texted me a YouTube video that explains this phenomenon and what to do about it.

So, if you just dropped $100,000 on a new Cybertruck, can you rest assured that your vehicle won’t rust? Gordian Hense, Managing Director for an automotive magazine focusing on in-depth analyses of vehicle durability and material sciences, answers that question: “It’s a misconception that stainless steel is completely immune to rust. If exposed to high concentrations of salt, such as in coastal areas or from road salt used in winter, even stainless steel can develop surface rust.”

How can stainless steel rust? To answer that, you need to know what makes stainless steel stainless.

Why Is It Called Stainless Steel?

Steel is an alloy of iron, nickel, carbon and other elements, but what makes it stainless is the addition of chromium at a concentration of at least 10.5% of the alloy’s content. Chromium is a super-hard metal—almost as hard as diamond—and it’s highly resistant to corrosion.

Not only that, but chromium combines with oxygen to form a protective chromium oxide layer on the surface of the metal. Even if scratches do occur, the protective layer self-heals and protects the iron in the alloy from the oxygen exposure that makes it rust.

Can Stainless Steel Rust?

Yes, stainless steel can rust. Hense writes: “According to a study by the International Stainless Steel Forum, stainless steel exhibits excellent corrosion resistance, but pitting can occur when it comes in contact with chloride ions.” Exposure to chlorine-based bleach or cleaners, for example, has been known to cause pitting in stainless steel sinks, because chlorine attacks the chromium-oxide surface layer of the metal and wears tiny holes in it. That’s pitting.

Salt is sodium chloride and it releases chloride ions when it dissolves in water. Does this mean that you’re exposing your expensive Cybertruck to possible corrosion when you don’t protect it from salty air or road salt? The chances aren’t zero, but Hense notes that the Tesla Cybertruck’s body is constructed from 30X cold-rolled stainless steel. “It’s known for its impressive durability and corrosion resistance,” he says, so it would probably take an unusually long period of exposure to salty conditions for it to rust.

Tips to Prevent Rust on Stainless Steel

Whether it’s a stainless steel sink, a refrigerator or a new Cybertruck, the most important way to prevent rust is to avoid contact with chemicals that cause it. They include:

• Sources of chlorides: They include salt, chlorine bleach and cleaning agents that contain chlorine. If you drive your Cybertruck in a community that uses salt on the road, clean your vehicle frequently to wash off salt deposits. If you live near the ocean and the air is salty, keep your vehicle covered or park it in a garage.
• Acids: Hydrochloric acid (HCl) and muriatic acid (a weaker type of HCl) can quickly cause discoloration and pitting, and so can other acids, such as sulfuric acid, in high concentrations. Avoid cleaning products that contain them. Even weaker acids like the phosphoric acid in fizzy soft drinks, the citric acid in lemons and the acetic acid in vinegar can stain stainless steel if they remain in contact long enough.

FAQ

How do you remove rust from stainless steel?

If you’re talking about rust dust, my nephew explained that a major source is the wheels or railroad cars, which produce microscopic specks of iron as they grind against the tracks. These specks can linger in the air, settle on the Cybertruck’s panels, cause surface discoloration or even embed themselves in the finish.

As explained in the video linked above, you can clean off rust dust with a combination of an abrasive cleaner like Barkeeper’s Friend and a non-ammonia window cleaner like Sprayway Glass Cleaner.

You can find other methods for removing rust from household items here.

About the Expert

• Gordian Hense is the Managing Director of Carmart.ch.