Umpteenth undercoat thread

[JerseyLariat]

Please ignore if you're annoyed to see another one, especially from a n00b.

Just bought a 2023 Lariat and we live in NJ in the NYC metro, so I expect lots of salt, and we park outside until/unless we add a garage. Also noticed beginnings of light surface rust in the usual areas.

I'm weighing undercoats because I don't trust myself to stay on top of washing and protection and reached out to a few places and here's what I've heard so far:

Talked to a nearby NHOU dealer and was impressed by the thoroughness of the process he described (removing spare, masking everything, spraying inside frame and doors--he acknowledged they are aluminum but said in this weather you can still get boat-style white corrosion). He claimed familiarity with Lightnings. Quoted $1,100 initial with $150 touch-up every one-two years depending on use and said to *not* wash under in-between. Also said they do not remove existing rust unless heavy as the coating neutralizes it.

Another place does Fluid Film for $300 with no reapplication unless I'm constantly power washing. They clean the undercarriage before application (due to my specific questions, I think they meant including removing the light rust, though it's not 100% clear).

Closest Corrosion X is way too far for me, and haven't heard back from Woolwax place yet.

I'm not looking to pinch pennies since we want to keep the truck a long time and our area is super salt-happy, but I don't want to just be a sucker for no reason. I like my impression of the NHOU place, but obviously the price difference is worth a moment to think about. Would appreciate any thoughts anyone wants to offer on these, and would really value personal experience with any particular process--or none--in similarly tough conditions.

Thanks!

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[RickLightning]

Your title says "Umpteenth undercoat thread", implying you found and read all the other ones. So, what's unique about your situation? And, in the other ones, did you find any that said "yes, you should undercoat"?

We've lived in northern areas all our lives. NJ, MA, PA, MI. All salt. Never undercoated, and since exhaust systems were improved never had any rust issues to speak of.

 

[21st Century Truck]

I strongly suggest AMSOIL Heavy Duty Metal Protector. Best stuff out there IMHO. There's an extensive thread on this vs. other undercoatings somewhere on the Gen 14 F150 blog.

It can be self-applied albeit with a good fume mask on. My Lightning took about four cans of this stuff a year ago. It's still on there, even with 15 thunder runs on the Bonneville Salt Flats Speedway this past August and the post-Bonneville multiple underbody power washings.

 

[WXman]

On my 2019 Super Duty, I bought a box of PB Surface Shield (6 aerosol cans). I was able to coat the entire chassis front to rear with 3 cans. Did it myself in the driveway in one Saturday morning. Cost me $60 bucks for that box, and I used half so $30 bucks to do the truck. It sprays on easy. After 2 years of winter salt, calcium, and magesium chlorides on our roads my chassis still looked brand new.

I was going to use the 3 cans I still had in storage on this new Lightning as soon as I got it home while the frame was clean, but my wife either threw the box away or I misplaced it myself and forgot about it. Sigh.....

 

[JerseyLariat]

Your title says "Umpteenth undercoat thread", implying you found and read all the other ones. So, what's unique about your situation? And, in the other ones, did you find any that said "yes, you should undercoat"?

We've lived in northern areas all our lives. NJ, MA, PA, MI. All salt. Never undercoated, and since exhaust systems were improved never had any rust issues to speak of.

Nothing unique, just that I have this particular solution space and it's still a relatively new type of vehicle so people's impressions may have evolved since the last threads. Plus in my experience some people on sites of this type enjoy sharing, even on topics that have been covered. I've done a fair amount of research across this site and others, AIs, etc, I just like to be very thorough on big decisions like this, and I feel like knowledge is always evolving. Appreciate the feedback about your non-undercoated experience.

 

[JerseyLariat]

I strongly suggest AMSOIL Heavy Duty Metal Protector. Best stuff out there IMHO. There's an extensive thread on this vs. other undercoatings somewhere on the Gen 14 F150 blog.

It can be self-applied albeit with a good fume mask on. My Lightning took about four cans of this stuff a year ago. It's still on there, even with 15 thunder runs on the Bonneville Salt Flats Speedway this past August and the post-Bonneville multiple underbody power washings.

That sounds like a pretty good test. When you've done it, did you drop the spare and do a bunch of masking, or maybe just do something more targeted like welds, the bare metal on drive shafts, the suspension arms, etc? Did you make an effort to get inside frame rails?

 

[21st Century Truck]

That sounds like a pretty good test. When you've done it, did you drop the spare and do a bunch of masking, or maybe just do something more targeted like welds, the bare metal on drive shafts, the suspension arms, etc? Did you make an effort to get inside frame rails?

I put the truck, rear then front, up on my trusty Canadian Pro Ramps, crawled under each raised end and sprayed AMSOIL HD MP up all over, into every rail opening and joint crevice, into every drain hole including on all (open) doors, and onto every accessible metal surface and into every metal hole.

This stuff is long-term STICKY and it's still on there after last Winter's 2+ snow storms and the attendant ice and salt. I was just under the truck for PMCS checks after our long Summer camping coast-to-coast trip which included the Bonneville thunder runs. Zero rust anywhere.

I used a Home Depot handy clip-on can spray trigger available for small change at their paint department, which helped A LOT, and I almost exclusively used the attached AMSOIL red spraying straw rather than a wide blast of can spray. I also had goggles on as well as an OSHA-rated nose + mouth mask I use for woodworking. While spraying, the fumes create a nice under-car cloud I would not recommend inhaling. There was also quite a bit of sticky overspray in the air, so we moved other cars out of the driveway.

All in all, the job took an hour or so on a nice Fall day last year, taking it slow and careful, for both ends of the truck... and the labor cost was free, which is a great price Besides, doing it myself ensured a good standard of completion vs. hoping that the 19-year old in the local undercoating franchise would pay proper attention to all the crevices instead of daydreaming about his date later that evening.

IMHO the cost of AMSOIL and the time spent seems to have insured preservation of the underbody likely for several years if not for the life of the truck. Thinking back, I think I used almost four cans of the AMSOIL HD MP, so I would not recommend getting more than that... the enormous central battery box, which of course got its own coating, eliminates a lot of crevices a regular truck would have, so the detail work = both ends and the sides of the rails & door areas.

Hope this info is helpful.

 

[Heliian]

Quoted $1,100 initial with $150 touch-up every

My dealer recommended against undercoating, it can actually cause more problems.

Regardless, anything more than 300$ is ridiculous and you're getting ripped off, run away.

If you drive into an ocean then you might see some corrosion, otherwise, leave it.

Fun fact, storing your truck in a heated garage increases corrosion due to the melting and salt moisture spreading.

 

[ClevelandBeemer]

The real question is do these trucks actually need to be coated? If you’re getting an undercarriage wash once a week during the winter does it matter?

 

[JerseyLariat]

The real question is do these trucks actually need to be coated? If you’re getting an undercarriage wash once a week during the winter does it matter?

I honestly have no idea, which is part of why I was asking; I've never owned a truck in this climate. I was frankly shocked to see rust underneath a modern vehicle that hadn't been damaged. I see it on the front A-arms, the drive shafts, and a little orange haze near a few frame welds. I have a 10 year old Ford C-Max that I drive in salt and snow without a thought and have *never* washed the underside in the 5 years we've owned it and I looked underneath yestereday and there isn't a hint of rust, not even on the seams of the frame.

 

[JerseyLariat]

I put the truck, rear then front, up on my trusty Canadian Pro Ramps, crawled under each raised end and sprayed AMSOIL HD MP up all over, into every rail opening and joint crevice, into every drain hole including on all (open) doors, and onto every accessible metal surface and into every metal hole.

This stuff is long-term STICKY and it's still on there after last Winter's 2+ snow storms and the attendant ice and salt. I was just under the truck for PMCS checks after our long Summer camping coast-to-coast trip which included the Bonneville thunder runs. Zero rust anywhere.

I used a Home Depot handy clip-on can spray trigger available for small change at their paint department, which helped A LOT, and I almost exclusively used the attached AMSOIL red spraying straw rather than a wide blast of can spray. I also had goggles on as well as an OSHA-rated nose + mouth mask I use for woodworking. While spraying, the fumes create a nice under-car cloud I would not recommend inhaling. There was also quite a bit of sticky overspray in the air, so we moved other cars out of the driveway.

All in all, the job took an hour or so on a nice Fall day last year, taking it slow and careful, for both ends of the truck... and the labor cost was free, which is a great price Besides, doing it myself ensured a good standard of completion vs. hoping that the 19-year old in the local undercoating franchise would pay proper attention to all the crevices instead of daydreaming about his date later that evening.

IMHO the cost of AMSOIL and the time spent seems to have insured preservation of the underbody likely for several years if not for the life of the truck. Thinking back, I think I used almost four cans of the AMSOIL HD MP, so I would not recommend getting more than that... the enormous central battery box, which of course got its own coating, eliminates a lot of crevices a regular truck would have, so the detail work = both ends and the sides of the rails & door areas.

Hope this info is helpful.

Did you try to coat everything metal, or did you just do critical areas like seams, welds, and bare metal?

 

[21st Century Truck]

Did you try to coat everything metal, or did you just do critical areas like seams, welds, and bare metal?

Per my post above, "I... ...sprayed AMSOIL HD MP up all over, into every rail opening and joint crevice, into every drain hole including on all (open) doors, and onto every accessible metal surface and into every metal hole. "

 

[JerseyLariat]

Per my post above, "I... ...sprayed AMSOIL HD MP up all over, into every rail opening and joint crevice, into every drain hole including on all (open) doors, and onto every accessible metal surface and into every metal hole. "

Don't mind me, I'm sure I got that the first time, but I skimmed revisiting it when I came back to the thread for a different reply and missed that. Thanks again!

 

[21st Century Truck]

Don't mind me, I'm sure I got that the first time, but I skimmed revisiting it when I came back to the thread for a different reply and missed that. Thanks again!

No sweat. Enjoy Your truck for a long time... it's all that really counts

 

[Henry Ford]

What problem does undercoating solve? Surface rust on the frame is a cosmetic issue. In my opinion, black oil on the frame is also a cosmetic issue.

I guess if you really hate the sight of rust when you get down on your hands and knees it's worth doing. I'll use my appearance budget for ceramic coating and carwashes.

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