Cybertruck Body Rust

[TugboatEng]

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?

 

[TugboatEng]

Do you specify NEMA 4X enclosures?

 

[JohnRBaker]

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

 

[EdStainless]

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

 

[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. 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.

 

[Brian Malone]

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

 

[dik]

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

 

[JohnRBaker]

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

 

[EdStainless]

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