Brand new vehicle undercoating.

Euroskank · February 21

Providing it doesn't end up at the bottom of the Red Sea, I'm about to become the proud owner of my first Lexus - a brand new NX 350h.

I live in a coastal city in north Scotland so they tend to put a fair bit of salt and grit on the roads from October to April, therefore, I'm thinking of protecting the vehicle's underside. Does anyone have any advice on undercoating the car as I plan on keeping it many many years?

EP80 · March 2

Do you plan to apply it yourself or get it done at a garage?

Euroskank · March 2

1 hour ago, EP80 said:

Do you plan to apply it yourself or get it done at a garage?

A local specialist will carry out the job. According to them they will powerwash and mask everything up.

"...underbody stone chip protection coating, its essentially a bit like rubber...."

£500 once-only application. Three days turnaround.

Boomer54 · March 2

On 2/21/2024 at 5:11 PM, Euroskank said:

Providing it doesn't end up at the bottom of the Red Sea, I'm about to become the proud owner of my first Lexus - a brand new NX 350h.

I live in a coastal city in north Scotland so they tend to put a fair bit of salt and grit on the roads from October to April, therefore, I'm thinking of protecting the vehicle's underside. Does anyone have any advice on undercoating the car as I plan on keeping it many many years?

Regarding advice be aware if it's the 'black' stuff these days it brings an advisory on MOT's to the effect the underside is not visible. When transparent stuff is now available it's easy enough to avoid that.

Linas.P · March 2

2 hours ago, Euroskank said:

A local specialist will carry out the job. According to them they will powerwash and mask everything up.

"...underbody stone chip protection coating, its essentially a bit like rubber...."

£500 once-only application. Three days turnaround.

NOOOOO - please don't!

The coating which is essentially like rubber is meant for old cars, I would say even vintage/classic cars. Have you seen how underbody of RX350h looks (or any Lexus from last 20 years for that matter?)... it is plastic clad everywhere! So applying rubberised coating like on 1970s Ford Cortina is not the way to go.

What you need is to go to detailer and ask to apply something like Bilt Hamber Atom-Mac or Hydrate 80.

https://www.in2detailing.co.uk/collections/corrosion-rust-treaments/products/bilt-hamber-atom-mac?variant=32326776291407

https://www.in2detailing.co.uk/collections/corrosion-rust-treaments/products/bilt-hamber-hydrate-80?variant=39561981001807

And it looks something like this:

After that if you really want to go above and beyond - you can ask all the plastic panels to be removed and underside of the car to get ceramically coated, so it is basically becomes hydrophobic. But that is really unnecessary. What usually happens to newer Lexus is that exposed suspension components, bolts in particular get's rusty, everything under plastic covers are usually fine.

SH20 · March 2

I agree with Linus. Today's manufacturers have ensured their bodies do not corrode unlike in the 70's when rubberised sprayed on underseals were all the rage but eventually merely covered a rotting shell behind the rubber coating. It formed a mould of rubber over factory finished painted steel. Done with the best intensions but when moisture got behind the covering it rotted out chassis legs, side members and floors discovered 5-6 years later when finally the MOT man was able to poke through the moulded rubber with his screwdriver to discover crumbling wet and rusty remains. The chassis leg etc looked like it was still there because the rubber stayed in place as a moulded replica of the part it was supposed to protect. Stay clear. Just look at any 20 year old Japanese vehicles or British made cars for that matter which 1. are still around and 2. Have good bodywork and chassis still.

Malc1 · March 2

……… and never been undercoat / “ protected “

I’d be amazed if a modern day new car couldn’t last 20 years before becoming an MOT Advisory for rust ……. except the exhaust course

We are no longer in the realm of 1970’s Lancia dreadful steelwork

Malc

Euroskank · March 3

That's good to hear, thanks. I plan on keeping the car for over twenty years that's all, and I was of the opinion that even if the chassis was behind plastic panels it could eventually corrode, and where I live that rate of corrosion can occur very fast.

Spacewagon52 · March 3

You might wish to consider Lanoguard - it needs applying once a year but it has a very good reputation. Belt and braces?

Malc1 · March 3

Plastic panels protection is a new one to me 🤔……. what happens if the plastic gets damaged, let’s in water that just sits there corroding away not breathing 😰

Doubtless new vehicle design takes account of all that 🥳🥳🥳 …… to my mind maybe some design built-in obsolescence to last the likely life of any new car, 10 years?? before the electronics jump out and bite ya 🥵

I might not be the person you want to listen to here ……. others might have different more rational thoughts 🤞

Good luck

Malc

Linas.P · March 3

1 hour ago, Euroskank said:

That's good to hear, thanks. I plan on keeping the car for over twenty years that's all, and I was of the opinion that even if the chassis was behind plastic panels it could eventually corrode, and where I live that rate of corrosion can occur very fast.

As it happens I own nearly 20 years old Lexus (2005)... does it have rust? Ohhh yeah! But more important question is what kind of rust it has... So first of all it is clear that it wasn't always cared for, there is little spot of rust where rear fender was scratched (so accident damage), the suspension bolts and nuts in particular have rust on them (I was told by mechanic this is typical for all Japanese cars, compared to say German), there is rust around lifting points (so again damage from improperly lifting the car) and exhaust is rather rusted (so that is wear an tear)... but there is no rust whatsoever on typical spots for older cars, floors, sills, inner fenders etc, because all that is covered by plastic. What is most important - all the areas that would be protected by "rubber undercoat" are not rusted.

That is not to say rust protection is not needed, but as I said the focus should be primarily suspension components, not the underside of the car. Also they will rust anyway, if not themselves then they will be covered by brake dust which will rust on top of them. But using something like Bilt Hamber Atom-Mac is basically what is needed, something that could easily be sprayed on intricate links and suspension components. You can even do it yourself, it requires application maybe every 2-3 years, but as a matter of routine could be done once a year. The process itself would be rather simple - lift the car (ideally without damaging the floor 😄), remove 1 wheel (if you have nice even parking and jack stands could be done on all 4 wheels), spray it with APC, let it sit for 5 minutes, pressure wash all the lose dirt, let it sit for maybe 15 minutes for most of the water to run down (compressed air would be ideal here), then spray Atom-Mac focusing on suspension components and all of key things can be reached easily from wheel well. Also wand sprayer (like the ones used to kill weeds in garden) are ideal for this. Repeat on all 4 corners and your car should be protected from rusting for good 3 years.

SH20 · March 3

Perfectly understandable about wanting to protect a brand new car from the start and climate plays it's part of course, hot dry countries no real rust issues ever, humid wet coastal areas, a very different effect on metals.

Still believe that the current assembly methods, factory applied corrosion protection and lots of "Shielding" in critically wet areas will do their job very well in the UK. As Linus said some rust is a direct consequence of careless jacking the car up by garage staff or owners, stone chips left unattended leading to surface rust/blisters, any damage caused by scrapes, scratches that are left to fester will give the impression of a rusty car but excluding these examples of rust a modern Lexus will have a standard perforation warranty of the bodyshell. Highly unlikely you will ever experience rust eating it's way out from the inside, inconceivable really if we are being honest about how cars are built today. Once a car Manufacturer got a reputation of corrosion such as Lancia then they simply never recover. I once requested an owner pay towards a new scuttle panel (Below the front screen) as part of his insurance claim I was dealing with because the rot was so bad it could not be saved. Had the panel been rot free it would have repaired easily. He was so glad he could tell Lancia UK his insurer was asking him to contribute due to corrosion who had been turning down his many letters of complaint he made about corrosion to the bodywork before his accident. He now had proof that he had a case. The car in question, a 2 year old Lancia Fulvia. Should have been called a Lancia Lace Curtain.

One thing that has taken off for older cars which totally transforms a car is dry ice cleaning (see Youtube videos). The point I am making about dry ice is that the car's all seem totally solid to begin with but the dry ice cleaning gives it that 95% new look when it was built. No matter what the dry ice touches it total restores how the part looked originally without destroying the more delicate bits such as painted parts, original corrosion finishes, sealers on joints, suspension parts, bolts in particular. It's usually something for people who want to restore a car. Some of the YouTube videos have to be seen to be believed. I've seen videos of cars that are only a few years old being treated and the owner wants that new look again. Engine bays look really good too.

Conclusion: Enjoy your new car and clean it/wash it regularly and correctly using a pressure washer periodically under wheel arches etc. Attend to any defects immediately even if it's small enough for a touch up stick. If you are inclined get a decent set of car ramps which will allow you to raise either end of the car so you can have access to areas of the car that are difficult to reach if the coastal salt water is a concern.

Bluemarlin · March 4

I would apply the Dynax products to the underside. Easy to DIY as they come in a can with longish lance attachment, so you can get into any cavities. I'd also remove the arch liners and apply it there. Once dried I'd give everything a spraying of ACF 50.

The Dynax should last 2-3 years (longer behind the wheel arch liners), but I'd reapply the ACF 50 annually, as it only takes 20-30 minutes.

It the roads are regulary salted then I'd also periodically rinse the underside with a lawn sprayer. The ACF 50 should survive a few rinses over winter.

Euroskank · March 5

Thanks, all, very much for your detailed responses. She arrived in Portsbury yesterday according to the maritime tracking site I was logging into every few hours! Now I just need to research the most cost-effective way of how to travel down to Lincoln from Aberdeen.

GSLV6 · May 27

I would strongly recommend you get it Lanoguarded underneath. You can book it in or do it yourself if you can get under the car. Best product for underside protection I've ever come across. I would not recommend the gunky black stuff, any of it. It hides any corrosion setting in, inevitably hardens, cracks and traps moisture. Lanoguard is a Lanolin based substance which you can spray or brush apply to the whole underside. I won't harm plastics and can even be sprayed on the cat and back box with no fire risk. It dries to form a highly resilient bond with metal, allowing total protection against water and salted roads. They say it lasts up to 3 years per coat but I had a toyota Rav 4 and my RX3 done and years later, it was still doing its job, with no risk of mot advisories as it leaves the substrate visible for inspection. No brainer living near the coast. Not that expensive either.

Euroskank · May 30

Thanks, for the time being I've opted not to go ahead with protecting its underside.

August 6

I'd not worry - here's the thing, the modern cars are all well protected from the factory. Only thing that can breach it is stone chip / scratching that goes through the galvanising layer... but then, if you get an undercoat and it gets breached the same way... same ingress chances for rust, right?

I'd also be scared on a brand new car of letting anybody, even Lexus, take it apart and refit things... Maybe it'd screw you over warranty wise if you had an issue and Lexus notice it was heavily worked under.

I've owned / maintained various little Fiat's in the family and what's said above, about most cars making it to 15-20 years before rust is even bad enough to be an advisory, is true on those little cars. No doubt Lexus is the same.

Hope you're enjoying your new NX350h - I bet it's some machine