[bradfa]

  So everybody smartened up and now things are much better, to the point that there hardly are cars made that have serious rust issues.

I find this entertaining. Come to upstate NY, USA where we liberally salt our roads in the winter. Definitely not "everybody" smartened up as it's still very common to find vehicles here that after 10 years should be declared unsafe to operate due to rust-through of critical structural components.

[jacquesm]

Interesting, any particular brands or is that across the board?

Here we liberally salt our roads as well in winter and in the past cars would not last a decade before falling apart. Now you really have to look to figure out which cars are new, 10 or 20 years old. Rust is - as far as I can see - a solved problem. Not many US cars on the road here though.

[bradfa]

Chevrolet and GMC full size pickup trucks and SUVs are probably the worst offenders. Which seems counter intuitive since many of GM's engineering and design happens in northern climates with salted roads. It's not all of GM's vehicles which are subject to this, many do have good corrosion resistance, they just choose to only use such techniques on a subset of the vehicles they produce.

For example: https://static.nhtsa.gov/odi/tsbs/2020/MC-10178959-9999.pdf

A few years back now Toyota had a big recall on Tundra pickups for improperly applied corrosion prevention. I'm to believe they corrected this as it was quite expensive for them to repair so many customer vehicles.

[ghaff]

Just had to get rid of a 2011 Toyota SUV because corrosion on a hydraulic line cascaded to other problems. (Was overall in good shape but some sort of chip or other problem on the line caused issues.)

[rasz]

>A few years back now Toyota had a big recall

Mustie1, absolute YT gem of a human being, did a couple videos showing his efforts to salvage post recall Toyotas. Recall was a scam. Instead of replacing bad frame, or stripping, cleaning and repainting Toyota opted to pay third party contractor to just spray some black goo on frame rails so they last 12 more months while the goo hides corrosion (and traps more moisture speeding up the process).

RRRUST 2013 https://www.youtube.com/watch?v=9s7N8QEAAeM

toyota 4runner frame rust repair 2013 https://www.youtube.com/watch?v=gBB8YX1I1QU

more toyota frame repair 2013 https://www.youtube.com/watch?v=hdLNKOdi4-A

Toyota Tundra frame repair 2016 https://www.youtube.com/watch?v=5IBXYnYYccI

toyota tundra rusted frame repair update 2 winters later 2018 https://www.youtube.com/watch?v=nn-cqoVYQR0

TLDR involved welding plates to replace eaten metal and regularly coating in oil/liquid film protection every year.

[bradfa]

Interesting. It was my understanding that the official Toyota procedure involved lifting the cab and bed off the existing frame and transplanting all of the rest of the truck to a new frame.

This seems to outline the requirements: https://static.nhtsa.gov/odi/tsbs/2019/MC-10154787-9999.pdf

The warranty work is listed at about 40 hours of duration for frame replacement, which seems rather short to me. For about a million potentially affected vehicles that's not a cheap recall.

[rasz]

Maybe thats what they were supposed to do, but the post recall trucks Mustie1 worked on all looked the same - spray of hard coat over the corrosion/holes the size of a fist.

[mlyle]

A big part, I think, is differing European attitudes towards maintenance. If there's a bit of coating damage and a rust spot somewhere detected by a mechanic in the US, everyone involved is likely to shrug and not bother with any remediation. The customer doesn't want to pay to prevent a problem that will manifest in years, and there's more lucrative work the mechanic could be doing.

[JohnBooty]

Do aftermarket "anti-rust coatings" actually work? Y'know, the kind people are always trying to sell you at auto dealerships and the like?

[buildsjets]

They typically make rust and corrosion WORSE, not better. They remove factory lee plugs to spray their anti-corrosion goo in, then often fail to reinstall them or do it poorly. Their goop can clog the engineered drainage paths and cause water to accumulate and sit. Some places even drill additional holes thru virgin metal to access hidden areas, which damages the finish and exposes unprotected areas.

[jacquesm]

> Some places even drill additional holes thru virgin metal to access hidden areas, which damages the finish and exposes unprotected areas.

That's an exceptionally bad idea for another reason: cabling is often sandwiched in between two layers of sheetmetal to protect the loom from mechanical damage. If you start drilling holes in box members there is a fair chance that you'll end up doing damage to whatever is enclosed. And of course the debris from the drill is an excellent way to start the oxidization process.

[jacquesm]

That depends on the state of your paint. If the paint is still good it will help a bit because the coating will take some of the wear. But if the paint is already damaged then rust will have started and applying a coating on top of that won't make much difference, though it may slow things down a little bit.

The best protection against rust is to keep your car clean, especially from leaves, bird droppings and other debris. Wash but not too frequently and if there are scratches or other minor issues fix them immediately.

[JohnBooty]

I appreciate this reply, thanks.

[bradfa]

Yes if you use a liquid one like Fluid Film. No if you use a “hard” coating like Ziebart.