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Cybertruck Body Rust

Cybertruck Body Rust

Cybertruck Body Rust

(OP)
I know this is being weaponized against against Tesla for obvious reasons but I also believe this is going to be a serious and real black mark against the company. Stainless steels don't tolerate dirty environments and road dust plus morning dew constitutes a dirty environment. I feel, not knowing the specific alloy, that these bodies are going to require regular abrasive cleaning or caustic+acid washing. Tesla hasn't said much about the alloy other than giving it a fancy name like 30X Hard. I assume 30X refers to a 300 series stainless steel which are especially sensitive to crevice corrosion. Maybe 305, a deep drawing stainless is the material?

RE: Cybertruck Body Rust

The only obvious reason is Tesla is famous for poor fit and finish. They managed to bring back a level of build quality the US automakers managed to escape in the 1970s and fit and finish in the 1970s still stunk. I recall a radiator strap that was cushioned with actual interior grade corner trim, complete with faux-wood finish, as one might get at a big box building supply.

Not to worry, the non-stainless frames underneath will likely self-destruct before the first hole corrodes through.

What is more likely to happen is what happened to a large number of Deloreans when owners discovered that trying to deal with any abrasion, scratch, dent, or other surface defect was met with the nearly impossible task of trying to match the brushed surface and so they gave up and got the car painted.

RE: Cybertruck Body Rust

Hard to believe they didn't notice this during the rather long development of the truck. My experience with SS is that 304 is only sort of stainless, but have rejected a batch of 316 that was almost as bad.

Cheers

Greg Locock


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RE: Cybertruck Body Rust

Oh, it was probably noticed, but you can't tell the great leader that one of his ideas is bad. "You will make this work, or I will find someone who can." Yes, boss.

RE: Cybertruck Body Rust

My son has 2 Tesla's, have friends with them. So far, we have not seen any problems with fit/finish. We have checked.
I guess the wash test on the Cybertruck wasn't enough?

Chris, CSWP
SolidWorks
ctophers home

RE: Cybertruck Body Rust

If the alloy is high strength I suspect that it is a 200 series alloy.
With the extra Mn and N they like to roll to very high strengths.
In many of these grades you can get 150ksi UTS/125ksi Yield/20% elong.
And crevice corrosion on dirty SS is very common.
Just wait until someone puts a sticker on it and ends up with pits outlining the shape.
One of the real problems is that wherever you touch it with a steel item you will leave a trace of material.
And this will start rusting. And while it isn't het SS rusting it leaves a rust streak.
And it does make it more likely that the SS beneath will pit also.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: Cybertruck Body Rust

See how hard it is for Tesla to escape their first many years of sloppy production?

It still surprises me that a bare metal finish on a vehicle was put into production. Chrome is barely up to the job as I recall from the rusting chrome bumpers and wheel nut covers.

RE: Cybertruck Body Rust

I have ridden in the Allegheny Ludlum SS Lincoln, and I have seen the older ones.
They used to let salesmen drive them around all of the time.
The only rules were that they had to be kept clean.
One of the guys told me that he had it washed twice a week so that it always looked good.
A bunch of these cars were sold in 2020, I am not sure where they are now.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: Cybertruck Body Rust

If I get a scratch in my car door, the body shop wants to paint the whole side to ensure a color match. I don't think Tesla ever advertised the finish as trouble free. As with anything new, the customers usually end up performing (and paying for) some of the R&D. Some new and innovative methods will be required to maintain and repair these. If you want to see corrosion, well, I'll just show you a picture of my 2500 HD (or any other vehicle) after a decade of parking lot dings and Ohio road salt.

Brad Waybright

The more you know, the more you know you don't know.

RE: Cybertruck Body Rust

One thing that aggravates the Tesla issues is that there is no one to go to get things fixed.
Just think of the mess if they ever need to physically recall vehicles.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: Cybertruck Body Rust

(OP)
I haven't seen one closely enough to see the surface finish. If they're brushed that can be repaired by hand. Tesla should provide a kit for customers with the correct chemicals and abrasives to maintain the brushed finish.

If they're media blasted or electrically finished, that would be a problem to touch up without having refinish the entire panel or body.

RE: Cybertruck Body Rust

I suppose Tesla will need to now use either a quality 321 stainless, or inconel.

RE: Cybertruck Body Rust

Why Inconel??? Very expensive and only needed for high temperature conditions.

RE: Cybertruck Body Rust

There are 10's of thousands, maybe more, subway, commuter, regional and long distance trains worldwide that are built from 300 series stainless. Mostly 304L, but also 301L.

They are not failing from crevice corrosion.

RE: Cybertruck Body Rust

(OP)
And 321 has similar corrosion resistance to the typical 304 grade and has less resistance than 316 which still isn't really suitable for this application.

Yes, if you get your nickel high enough you won't have crevice corrosion. That would be Inconel. You can save money on chromium and use Monel. 254 SMO would also work well.

Regular polishing or 316 stainless steel will work but that would change the appearance from brushed and this truck was advertised as being durable.

I figured this would be a good chance to introduce everyone to the concept of crevice corrosion. Most stainless steels are highly sensitive to this problem and it can happen in open air (air is dirty). I especially want our electrical engineers to see this and recognize the problems caused by spot welded flanges and hinges on enclosures.

Mint, I thought those bodies were aluminum. If SS, they also likely get regularly washed. There is a company, Integument, that applies fluoroelastomer films to those bodies. If there is corrosion, they aren't held to the same level of scrutiny. The Cybertruck bodies are staining, they're not failing in any serious way. Aluminum is also subject to crevice corrosion.

RE: Cybertruck Body Rust

Budd was building stainless passenger cars for years--since before WWII. Some are still around.

They likely didn't/don't get much salt exposure, though.



spsalso

RE: Cybertruck Body Rust

(OP)
Don't forget about Delorean. A bit of googling reveals similar issues. I don't think the Delorean was ever advertised as anything more than a novelty. Tesla maybe overstated what their body could do.

Budd also built a SS airplane.

RE: Cybertruck Body Rust

So, that DeLorean that I never bought would have had the same issues with the Tesla that I'll never buy... Yawn...

When one this sentence into the German to translate wanted, would one the fact exploit, that the word order and the punctuation already with the German conventions agree.

-- Douglas Hofstadter, Jan 1982

RE: Cybertruck Body Rust

(OP)
Do you specify NEMA 4X enclosures?

RE: Cybertruck Body Rust

When I was still working and when GM had purchased our software and I was spending a lot of time at the Tech Center in Warren, MI, and one of those times I got to visit one of their quality control labs. This was where they would take production vehicles, which had been used as demonstrators at a dealership or was a car that had been driven by an executive for several months, and they would literally tear them down to the last nut and bolt. And one of the things that they would spend the most time and effort on was looking for signs of rust or corrosion (and since most of these vehicles had been driven in the mid-west, they would try to get ones with at least two or three months of winter driving on them, subject to rain, snow and road salt). They paid particular attention to inside of all the door panels, body panels, anywhere water could have been captured without being properly drained, looking for rust. This was something that they were paranoid about, finding all these blind areas that you could only see by tearing the sheet-metal apart. It was either that, or wait until the rust ate through the paint two or three years later.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Cybertruck Body Rust

Don't forget that various 400 series ferritic alloys have been used for bright work on cars since the late 40's.
The controller of corrosion resistance (Cl pitting) in SS is the Cr (unless you are also adding Mo).
Everything else is there to control the microstructure.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

RE: Cybertruck Body Rust

What method can be used to do a spot repair of brushed stainless steel that will guarantee a match to the original grit size, depth, pressure, and lay? Obviously, lay can be observed and recognized but without machine/mechanical guidance matching lay by handwork is difficult. Small dents are extremely difficult since the grain is in essence creating optical fringe lines that highlights any waviness or imperfection. Low areas cannot be easily filled and blended with grained stainless. Generally, I have seen most spot repairs standout on stainless unless the complete panel is regrained from break to break. Then the grit size, pressure and depth must match the original lest the panel stands out. I think Tesla took a misstep on the material choice and finish. Standard steel and paint finish would have met most customer expectations and requirements, and the company would not have expended resources on perfecting a possible albatross technology/expertise.

RE: Cybertruck Body Rust

Additionally, any body repair work is going to extremely expensive - how many bodyshops and techs have the tools, expertise and experience to do repairs?

RE: Cybertruck Body Rust

Maybe a good reason to use a finish that can be readily replicated?

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

RE: Cybertruck Body Rust

Quote (Brian Malone)


What method can be used to do a spot repair of brushed stainless steel that will guarantee a match to the original grit size, depth, pressure, and lay? Obviously, lay can be observed and recognized but without machine/mechanical guidance matching lay by handwork is difficult. Small dents are extremely difficult since the grain is in essence creating optical fringe lines that highlights any waviness or imperfection...

And that's the same problem that they had with DeLoreans.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

RE: Cybertruck Body Rust

Next time you are in St Louis visit Gateway Arch.
Stand next to one of the legs and look up.
You will see three different surface finishes.
The spec was the same but the plate was supplied by three mills.
The rougher the finish the easier that it is to match.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

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