The Tesla Cybertruck’s bare metal panels are unique compared to the painted panels of most automobiles. Now that the truck is in the hands of customers, you may have read all the stories about the rust issues, as people learn how to care for stainless steel, and how it behaves out in the elements. Questions have swirled around whether the Cybertruck can hold up to the weather, and just what stainless steel is really capable of. Let’s take the Cybertruck as a jumping off point, and explore the reality of stainless steel in more detail.
The hubbub right now is that a number of Cybertruck owners have reported seeing rust spots on their vehicles, in some cases just days after taking delivery. This set off alarm bells, with outlets rushing to cover the story. Dig down into the forum posts, and it’s easy to see why some owners were getting upset. One poster known as Raxar shared pictures of small orange-brown spots peppering the body, as did OnTheSnap. and Vertigo3pc had a similar experience after a rain storm in LA.
Nobody wants a six-figure truck that looks like a crappy Walmart barbecue left outside in the winter. As good as the name “stainless steel” sounds, we’ve all seen some cheap stainless steel appliances plagued by the orange-brown rot of corrosion. Does that mean the same fate awaits the Cybertruck?
Speaking to The Autopian, vertigo3pc explained their discovery of rust marks on the Cybertruck. “I discovered the marks on my Cybertruck’s finish probably the fifth day I had the truck at home,” he explains, noting it was after a days-long rain storm in California. “I noticed the tiny spots on the right and left panels next to the vault.” The rusty-looking spots didn’t come off with the use of a clay bar, so he headed to the forums for answers. “I thought it was some sort of contamination, moreso than something sitting on the metal,” he says.
Multiple owners have since come forward to share similar photos of marks and rusty-looking spots on their new Cybertrucks. To understand what’s going on, let’s dive into some chemistry and see if learning about stainless steel can solve this problem.
Does Stainless Steel Rust?
Well, here’s where it gets complicated. Stainless steel is not one singular material. Instead, it’s a name applied to a great number of different steel alloys which are prized for being more resistant to corrosion than typical mild steels. Note that phrasing—more resistant. Not corrosion-proof, by any means. Nobody’s calling it “stainproof steel,” it’s stainless steel because it stains less.
That’s just wordplay, though (a joke). The true properties of any stainless steel alloy come down to its precise content and preparation. By and large, stainless steels normally contain at least 10.5% chromium, with carbon content anywhere from 0.2 to 2.11%. The chromium is the key components in its corrosion resistance. In stainless steel, chromium atoms in the alloy react with oxygen in the air to form a protective layer against further oxidation. This layer is only a few nanometers thick; for context, a human hair is around 50,000 times thicker. If this layer is compromised, such as by abrasion, further chromium atoms in the steel will react with oxygen and reform the protective layer. The process is called “self-passivation,” and it’s why many stainless steel items are able to last for decades without succumbing to rust.
Adding higher levels of chromium, or certain levels of nickel or molybdenum, can further improve the materials resistance to corrosion. That’s why some stainless steel items seem to rust quite easily, like cheap appliances, while others hold up far better, like quality stainless steel sinks.
Just because stainless steel doesn’t typically oxidize in open air, that doesn’t mean it can’t be corroded. Let’s explore grade 304 stainless steel as an example. Some grades, such as 304, are particularly susceptible to corrosion from chemical chlorides, with salt (sodium chloride) being perhaps the most common. Grade 304 stainless steel will tend to suffer pitting corrosion when exposed to salt water or salt spray. The mechanisms involves chloride breaking down the passive oxide layer on the surface, allowing corrosion of the iron content of the alloy itself. Once there is a small break in the passivation layer, a pit forms, in which a tiny electrochemical cell can be formed between the corroding metal and the base metal, which sustains the corrosion over time.
For demanding outdoor uses, grade 316 stainless steel is typically used. This grade is far more resistant to attack from chlorides, and pitting corrosion in general. This sees it used in things like street furniture and marine-adjacent applications. It all comes down to the molybdenum content in grade 316 stainless steel. The role it plays is complex, but in simple terms, it helps form a thicker passivation layer, and improves the layer’s ability to repassivate when damaged. This creates a stainless steel which is more resistant to attack by chloride ions than 304 stainless steel, which lacks the beneficial molybdenum content to support its chromium passivation layer.
Of course, you can’t just dump extra molybdenum into an alloy and call the job done. It’s not just about the input costs of the raw materials, either. Every tiny change to an alloy’s composition effects a wide variety of parameters. Crystal structures can change, affecting everything from strength to formability, melting points, and beyond. Picking the right alloy for a given application requires making the right tradeoffs between cost, manufacturability, and fitness for purpose.
You might want to make your car out of the most corrosion-resistant stainless steel possible, but then you find out it’s really expensive and nearly impossible to shape effectively. Thus, you have to compromise.
So what did Tesla use in the Cybertruck? Well, we don’t know. Tesla hasn’t specifically stated what alloy it uses in the Cybertruck’s body panels. We know the company refers to it as HFS, or “Hard Freaking Stainless.” As you might have guessed, though, that’s an internal term, not a common industrial grade of stainless steel. All we know is that CEO Elon Musk described it as a “ultra-hard 30X cold-rolled stainless-steel.”
Notably, being a 300-series stainless steel, it’s in the same class as the 304 alloy used in the body of the DeLorean. Ultimately, though, it’s hard to draw any direct correlations with the DeLorean without knowing its exact chemical makeup. In any case, the DeLorean was not free of corrosion concerns. Panels can suffer pitting corrosion over time, even badly enough to eat through the 0.8mm-thick (0.03-inch) panels.
A Potential Explanation
There are other routes towards corrosion for stainless steels, too. One of the most common ways for stainless steel to rust is when it comes into contact with non-stainless steel. For example, using steel wool to clean stainless steel can leave tiny iron particles in the stainless steel which penetrate the passivation layer and enable further corrosion. Another common way it happens is when particulates from welding operations land on stainless steel in a factory environment. Cross-contamination can also occur when tools are used to cut both mild steel and stainless steel components. The presence of non-stainless steel particles can prevent the formation of a passivation layer in a small area, leading to corrosion.
Indeed, it may be iron in particulate form is the cause for the corrosion seen in some of these Cybertruck photos. We see tiny little spots where rust is occurring. These spots may be rail dust, tiny iron particles thrown up from train wheels and rails. Rail dust is a well-known problem in the car detailing community, particularly for people in areas with heavy rail use or for cars that have been transported via rail.
Rail dust can affect any car, but is most visible on light paint jobs. Once the tiny particles land on a vehicle, they can corrode on top of the paint – the problem has been around forever. The usual treatment to remove rail dust from a regular car’s paint finish is to use some kind of detailing product which dissolves the material. The solution is then washed off to avoid any damage to the paint.
Reports from the forums support the rail-dust hypothesis. Both posters mentioned above found success cleaning off the spots using a product called Bar Keeper’s Friend. It’s a popular product for cleaning stainless steel, particularly in the hospitality industry, and contains three main ingredients. It’s made up of feldspar, likely used as a mild abrasive, sodium dodecylbenzene sulfonate, which is a detergent, and citric acid. It’s the latter that probably had the most beneficial effect on the stainless steel of the Cybertruck, helping to remove any iron contamination on the surface. Once rinsed off, the stainless steel would be able to reform its chromium passivation layer, and the panel would look unblemished once more. That is, as long as the corrosion was treated quickly and not left too long. If corrosion took hold and created deeper pits in the surface, more polishing would be required to get back to a smooth finish.
Both OnTheSnap and vertigo3pc were happy to share their stories with The Autopian, and their photos in turn. Both used Bar Keeper’s Friend to clean their Cybertrucks, with positive results. “I usd the soft liquid variant of BKF,” explained OnTheSnap, adding “After applying it with a sponge I cleaned it off using Windex. He’s had little issue since, too. “It has maintained the same state.” He notes that he has also used the foam spray version of Bar Keeper’s Friend on the whole car since, which brought the shade of the stainless steel up to a lighter color. “So far it’s equivalent to owning a painted car that you wish to maintain, except I use Windex instead of water to quickly clean it” he explains, noting that he follows the typical guidance to remove bird droppings or other contaminants as he sees them.
As for vertigo3pc, he had similar success. “I removed the spots using Barkeeper’s Friend (soft version), using a tiny amount on the surface of a microfiber rag, and gently wiping over the spots,” he explains. “I assumed that wiping harder with BKF would definitely remove it, but also just using the rag wet with BKF soft also removed it… so I believed the BKF soft liquid had something to neutralize and remove the spots, whatever they were.” Since the treatment, he hasn’t seen the spots reoccur. He also tried an iron decontamination detailing spray from Chemical Guys, just in case. “After 2 rounds, I noticed no purple runoff, so I assumed the contaminants were gone,” he says.
“I found the best way to remove the spots was Barkeeper’s Friend Soft, followed by soap and water, followed by ammonia-free window cleaner and wipe dry,” says vertigo3pc. He’s contemplating adding a coat of Everbrite ProtectaClear in future to preserve the look of the stainless steel.
Of course, the corrosion could always reoccur if the trucks were re-exposed to iron contamination. If you lived in an area where iron particulates frequently came down with the rain, you could find yourself detailing the car fairly regularly. Indeed, the Cybertruck manual advises owners to “immediately remove corrosive substances (such as grease, oil, bird droppings, tree resin, dead insects, far spots, road salt, industrial fallout, etc).” At the same time, most automakers make similar suggestions for cars with regular paint finishes, too.
Supporting Evidence
It bears noting that Cybertruck lead engineer Wes Morrill has come out and stated that this type of corrosion is to be expected on the vehicle. On Twitter, he explained that iron particles sitting on the surface of the stainless steel will create corrosion, and that cleaning off with a solution like Bar Keeper’s Friend is recommended.
Good myth busting. Stainless is reactive and free iron that sits on it will rust. It's surface contamination only and can be cleaned off easily. Bar Keeper's Friend used here works well, citrisurf77 can also loosen the deposit and simply wipe it off. If anything stubborn use a… https://t.co/HD3Xeo0inH
— Wes (@wmorrill3) February 16, 2024
You can see Bar Keeper’s Friend in action in a video from Out of Spec Detailing. It doesn’t concern corrosion specifically, moreso how to generally detail the Cybertruck’s stainless steel panels. Regardless, it’s clear to see the effect of the cleaning product on the surface. As a mild abrasive and acidic cleaner, it does a good job of shining up the panels. Presenter Coleton recommends applying it to the entire vehicle to ensure a consistent finish across the truck.
Lots of Cybertrucks, near the delivery center in Austin TX
byu/GunGeekATX incybertruck
There is a large variation in color between panels on new Cybertrucks seen in many photos. One wonders whether a full-car detail could sort this out, or if it’s happening in pre-delivery.
Cold, Hard Reality
So, we’ve learned that stainless steel can indeed corrode, and the conditions under which that can happen. However, for now, it’s really too early to tell if the Cybertruck has a real corrosion problem. If you live right next to a railway, or you regularly transport your car via train, then yes, I’d suspect you might have some corrosion issues to deal with on the regular. Outside of that, it’s probably too soon to tell. Unless Tesla shares its alloy composition with us, or shows us the results of exposure tests that it ran on real panels, we won’t know for some time.
Ultimately, it could prove frustrating for some owners in areas where this kind of contamination is common. Nobody wants to be spending every weekend detailing their truck to avoid unsightly corrosion. While iron particulate contamination can stick in a regular clearcoat and appear ugly, you can at least rest relatively easy in the knowledge that it’s not going to cause too much problem for the metal underneath the paint. In the case of the Cybertruck, there is zero protective layer, so anything on the surface is interacting with bare metal. We should know in the next few months just how much of a burden—or not!—this will prove to be for Cybertruck owners. It may just be the case that a rub-down with Bar Keeper’s Friend once every month or two is enough.
If I had a Cybertruck, I’d be looking to the community to see what works and what doesn’t. I’d absolutely avoid using any steel wool or other iron products on the vehicle, and I’d try and keep the car parked somewhere where it’s not going to be exposed to contaminants like bird droppings or leaf litter. That’s just good practice for any car, though. I’d stop short of personally supporting the use of Bar Keeper’s Friend, having not tried it myself. It makes sense, but I’d hate to see anyone ruin their vehicle. Whatever you do, this sage advice always rings true: “Test on an inconspicuous area first.”
I hope this article has enlightened you to the magic (and limitations) of stainless steel. We might not have all the answers yet, but the science can point you towards the right (and wrong) things to do when it comes to taking care of your stainless steel vehicle. If you’ve got your own Cybertruck, reach out to us for a chat—we’d love to get more word about what’s happening on the ground!
Image credits: Tesla, Out of Spec Detailing via YouTube screenshot, Bar Keeper’s Friend, Carpro, Jason Leung
Engineer here – I worked approx. 20 years in the specialty steel industry (as a mechanical and machinery maintenance engineer – NOT a metallurgist). Stainless is a catch all for many various grades and compositions, most of which will absolutely corrode under unfavorable conditions. The 300 grades (austenitic) are pretty good at resisting surface corrosion, this what is used on your appliances and silverware. I have no idea what these are made of but keeping in mind that WE kept bright annealed cold oiled says something. I lightly wipe my brushed SS appliances with WD40 btw. No scouring pads or Scotchbrite.
One of my former employers sponsored a series of SS bodied car for Ford in the ’30s and ’60s. Look up the Allegheny Ludlum bodied Fords.
Huh. A great bit of history there. Really like the ‘36 Tudors—and the fact that the stamping dies were worn out after them.
Thanks!
Yes, my understanding is they were last cars off the line. The SS destroyed the body stamping dies. I have seen at least one example of each car up close – they still gleam as new.
“Nobody’s calling it “stainproof steel,” it’s stainless steel because it stains less.”
That’s not quite the etymology. Although their spellings have converged, “less” and “-less” have distinct origins and different meanings. The suffix means “without” as in headless or homeless, so the name “steel without stain” is a bit of an exaggeration.
Maybe he edited the article after your comment but the next sentence is now “That’s just wordplay, though (a joke).”
I’m really surprised the exact stainless blend isn’t know yet. I’m sure someone with access to a metal analyzer has gotten their hands on a CT by now.
There are almost certainly multiple grades on the car- you need different steel for areas that have bends and radii that will work-harden the piece (likely 307 steel) vs something in a big and flat panel where price and appearance become the primary concerns (likely 301 or 304). For virtually all purposes that matter to the end user, knowing it’s 30X steel is enough.
Hand held TXRF gun, any decent scrap metal dealer will have one.
Thank you for a detailed and unbiased explanation.
I have a stainless Ford Racing catback exhaust on my Mustang, and it likewise gets the little iron particles that start to corrode. But yep, a little scouring powder does the trick nicely, though eventually they do build up a little and create small imperfections.
Still, it’s been on there for 20 years and looks fairly good unless you get really close up. But what’s visible is just two pipes, not an entire body.
Those are often passivated from the factory, you can in fact passivate Stainless your self with chemicals, and you kind of have to if you weld Stainless as the welding process breaks down the natural passivation layer. the problem is the guy welding those mufflers in place rarely knows anything about this and they also use non-stainless welding wire, so the rust starts there and spreads an inch or so back.
these guys are going to touch their eyes and maybe other sensitive parts of their bodies after giving their truck a BKF bath and they’ll have to tweet that actually it’s good that they are temporarily blinded
actually, I wonder the environmental impact of washing all that BKF off the truck and into the sewers.
You mean storm drains which is different than an actual sewer because storm drain waters wash to rivers and the ocean untreated.
Storm sewers and sanitary sewers are both called sewers.
“Is that you Norton?”
Asked in best Ralph Kramden voice…
Very little. BKF is essentially glass beads, a plant acid, and a synthetic detergent. If you mix vinegar, shampoo, and fiberglass you’ve got something in spitting distance of it.
Thanks for that: I’ve idly wondered what was in it after using it on large plate glass windows during the construction cleanup of a high-rise
Its exact contents are further up in the article. The active (detergent) ingredient is sodium dodecylbenzene sulfonate. Not particularly dangerous to humans, but pretty toxic to fish if it gets in the runoff system.
Also like most other detergents, “safe” or not, SDBS uses up free oxygen in the water to break down. Most detergents have phosphates (this particular one does not), and phosphates lead to algal blooms, which further reduces oxygen when they decay, and can suffocate out life.
It’s been a frustrating road watching my state’s campaign to get people to stop just dumping shit in the storm drains, and now coming to a new threat with chemical breakdown of tires that people love to either just yeet into the woods or bury in their yards as planters, and the byproduct is neurotoxic to fish (specifically salmon).
Short moral of this story: if you wouldn’t want to drink something, don’t let it go down a storm drain.
I wish Tesla had skinned these things with copper. It oxidizes so much nicer.
Gonna look great in the midwestern winters
If I was dumb enough to have one of these vehicles, I would have it wrapped to look like it was made of plywood.
Or just go the whole way and get it galvanised.
The cheapest-looking, yet most expensive Woodie of all time. Love it.
I wonder if a ceramic coating would discolor the stainless steel?
Um, this seems like a PRIME opportunity to cross promote a certain partner to this website that markets high-end protective film.
If you’re trying to flirt to get David Tracy’s attention, you’ll need more rust than that.
The redheaded mustachioed man on the cover image – where is that from?
I found a cardboard cutout of that exact character in my basement after buying my place in Chicago. People have told me its “Handy Andy”, mascot for a Chicago home improvement store that closed for good in the 90’s… but I have yet to see an image online that matches the cutout. Your image does though…
Rusty Jones
Rusty Jones. Used to be a chain of rust proofing shops, kind of in the vein of Ziebart or Krown.
IIRC, Handy Andy had a comically oversized ball cap.
And here’s an ad from back in the day, one of the later ones:
https://www.youtube.com/watch?v=IvSm0wbi_cc
Rusty Jones, a gentleman who seemingly only appeared on rusty cars.
To me the photos don’t look like that the body itself is rusting. It looks like either brake dust or otherwise small metallic dust picked up from the road.
You mean like they said it was rail dust or other iron dust sitting on top of the metal?
Many houses around here, as well as the cars parked in front of them if they aren’t maintained properly, develop orange staining from irrigation systems spraying iron-rich hard water . I wonder how big a problem this will be for Cybertruck owners?
I feel attacked as this is my Saturday morning ritual. Cleaning the cars is “me time”.
Cleaning, yes. Getting “tennis elbow” from having to scrub every exposed square inch of one of these, not so much.
I love detailing my car, but it’s pretty small and I can get through it all including clay bar, polish and wax in 2-3 hours. This not only cleans my car but also improves the finish, polishing away and filling in any imperfections in the clearcoat, to the point that a great detail can leave the paint better than it left the factory due to flattening the orange peel effect. It’s extremely satisfying and quite relaxing as you just look for imperfections and tackle them in whichever manner you choose.
But with a stainless body, you have to follow the grain in perfect straight lines, knowing that your fleshy human arms will never achieve the precision of the robots that sand-brushed the panels at the factory. As a result, no matter how hard you try, anything you do to clean your stainless-bodied vehicle results in a WORSE finish as your fallible arms make a slightly-less-straight and not-quite-as-continuous finish. Detailing a stainless car sounds like a very stressful ordeal to me, and then you throw on top of that the sheer size of the thing, and you’re stuck for hours upon hours staring at the abyss of ruining your perfect finish with every stroke.
The obvious solution is to eat bacon every day, and then about once a week you take the grease jar out and treat your Cybertruck to a nice lard massage.
Yeah like they wouldn’t tell you no, you must only use Tesla-brand lard substitute. Preferably purchased as a subscription.
It takes decades of a grandmother’s loving care to truly and properly season a Cybertruck.
That color variation in the second to last picture of the truck. Jesus Christ. It’s like a rich poor-man’s Harlequin… Unimog? Like that but without besmirching Unimogs.
Back when I had my reservation I was actually looking forward to the surface rust. I think a patina would give it more character.
Definitely would add to the dystopian futuristic vibe it already has
I feel all that’s missing is a sticker of some sort of vaguely Japanese and tech sounding business/product.
It could make for some pretty sick Ghost In The Shell cosplay
I would also accept a Weyland-Yutani sticker.
Ok two things.
Wouldn’t mind seeing if Tesla did anything to avoid galvanic corrosion.
Hey, it’s got a stainless body with aluminum substructures and a whole lot of electricity running through it all. I’m sure we can drown these in water from above and salt slurry from below and not have any issues at all.
Of course it’s not a big deal. Anything with the cybertruck will only ever impact two populations.
First – it will bother the youtube nerds. The ‘content’ creators who needed to buy one to be the first to post a video about it. The more issues the better, because it’s more things to wrap 2 minutes of information in 20 minutes of garbage nothing. Hey, remember to like and subscribe!
Second – It will bother the second wave of people who will post videos about the same issues a year or two later. The regular nerds will be later to the game, but no less whiney about their stupid non-offroading, non-towing, non-hauling ‘truck.’
I am not just willing to see these two groups inconvenienced, I am pleased by their frustrations.
If I owned one of these, I’d probably periodically buff it with fine polishing compound and then use a hard wax, like carnuba, on it for final dressing.
But then, I never will, so it’s all hypothetical.
“Now, Biff, I want to make sure that we get two coats of wax this time, not just one.
…
“I’m just finishing up the second coat now.”
…
“Now, Biff, don’t con me.”
Coincidentally, I am currently sporting Christopher Lloyd’s hair style from that movie. It flounces magnificently in the wind when I drive my Miata topless.
Put a shirt on before some poor child’s mind is permanently warped seeing you topless behind that steering wheel!
Unfortunately one of the hard lessons learned in adulthood is that “Perception is actually more important than reality”
Indeed. According to Hindu/Buddhist precepts, humans rarely even glimpse reality, but instead live in a web of self-constructed illusion, built by the limitations of our own perception.
This is classically termed ‘maya’, and is one of the largest obstacles to enlightenment.
Came for the 40-year old Rusty Jones reference, fell ass-backwards into nirvana. What a great website!
And Plato was on board with this too – I’ve always thought the allegory of the cave in Republic is haunting for being both simple and deep. Like a lot of Greek philosophy, I always think of it being longer than it actually is.
Well said, Jack.
Your excellent post sent me back to a nifty little book I haven’t looked at in awhile – Karl Jasper’s Socrates, Jesus, Confucius, and Buddha. It examines the similarities and differences between their teachings, noting their relatively shared time period. So thank you for prompting me to think of it.
Interesting topic – just ordered a copy. Thanks gang!
The bigger issue is Tesla delivering a $120k vehicle covered in rust spots. If they are easy to remove, why even subject the company to such embarrassment?
Because a normal dealership would have a lot boy to shine these up before delivery. Elon does not like normal dealerships, or employees in general.
If he could have a drone drop these on buyers in their driveways, he would.
“If he could have a drone drop these on buyers in their driveways, he would.”
I thought the nefarious plan for all Teslas was Full Self Delivery.
Am I the only one that specifically tells the dealer to not have their
scratch-makerdetailer touch my car? Maybe I’m not buying expensive enough cars, but I’ve yet to seen a detail from a dealer do good work. I’m not blaming those guys either, they probably get paid too little, have shit tools/products, and have way too little time to actually do a good job.I’ve done it. And I’ve specifically requested that they skip the complimentary wash when I bring it in for service.
There is nothing more dangerous than a rotary buffer in the hands of a stoned juggalo.
Depends on the dealership. When I worked for a couple of dealers bac when we took pride in our work, and customers would come with non-dealership vehicles to have them detailed. If I’d had a camera phone back then I’d have made a portfolio from some of the before/after.
If your dealer is detailing your car without you specifically paying for it I think you’re buying too expensive cars. Even my truck, which is by far the most expensive new vehicle I’ve purchased, got nothing more than a wash prior to delivery. Ditto when I had it in for body work after it got hailed on. I can’t imagine any dealer I’ve ever dealt with detailing my car just for funsies.
You buy cars BEFORE they get hailed on? Shoot, my dad waits for a good hailstorm then goes down to the dealer when he needs a new farm truck
Smart man!