Thoughts on undercoating (1 Viewer)

[kcjaz]

I have never had any car I’ve owned undercoated. I grew up in the North and have some tolerance/acceptance for surface rust. I don’t need Arizona brand new looking perfect. That said, my new 2025 Tacoma is the first brand new vehicle I’ve ever purchased and I intend to keep it a long time so maybe doing some kind of undercoating before its first KC winter isn’t a bad idea.

The question is, what type of coating should I use? I don’t really like the oil or lanolin based type products because they seem to just sticks to it, makes working on stuff underneath messy, and they have to be reapplied every year. I think wax based products might be better in that regard but not sure. A rubberized coating seems like it would be good for a new vehicle but one thing I know about coatings is they are only as good as their application. Any defect that allows moisture under the coating will create the potential for hidden corrosion that would probably be worse than any surface rust.

So, that brings me to polyurethane or other paint type products. To me, these are the best but also the hardest to apply. I’ve thought about essentially painting the undercarriage with POR15 or other type paint, and then have a lanolin based products sprayed on the inside frame parts. I’m just not sure that much work is worth it.

What the Mudd crew doing with their new Tacos?

 

[TheBussman]

I've sprayed a few of the new tacomas. The new frame design is great, they did away with overlapping layers of steel. I'm sure they aren't going to get rust holes as bad as the older generations. i use the messy lanolin product. Your right is does have a downside but it totally works. I would look into wax undercoating, i think it could work well on a brand new truck and pickup less dirt. That being said it's not going to last forever, and years from now when it does get thin you'll have to recoat with lanolin to keep protection.

 

[Romer]

Never undercoated a vehicle so can't really comment other than I have no plans to. I haven't regreted it, but then maybe I don't know how nice it is Is it like seat heaters you swear you don't need them until you get a rig with it and then it becomes a required option from then on.

Like you, I also have a 200 series so between the two I don't put a lot of miles on either. In bad weather, I would drive the 200 as truck as a low weight back end than can slide easier on ice, even with sand bags. I didn't say will slide, I said easier than the 200 which is loaded with drawers, tools, parts, fridge, bumper, two spare tires and an Aux fuel tank all over the rear tires

 

[pappy]

Is it like seat heaters you swear you don't need them until you get a rig with it and then it becomes a required option from then on.

Funny, Ken. I specifically ordered my truck with bun warmers. It was not optional.

 

[Romer]

Funny, Ken. I specifically ordered my truck with bun warmers. It was not optional.

Wait until you are someplace freezing this winter. You will say the same about the steering wheel heater. Unless that was already required. It was for me after driving the 200 during the winter here in Colorado.

 

[pappy]

Wait until you are someplace freezing this winter. You will say the same about the steering wheel heater. Unless that was already required. It was for me after driving the 200 during the winter here in Colorado.

The heated steering wheel was part of the upgrade package with the heated seats. When I picked up my Dirtbox I drove home in a snow storm. I tried the heated steering wheel. Oh baby. I get it.

 

[cmw]

Having grown up in the Northeast I have learned to loathe rubberized undercoating. It may start out well but moisture will get behind it and very bad things start happening out of sight.

Plain old motor oil liberally applied every fall is a great start and really penetrates into the nooks and crannies. Lanolin based products are a big step up for durability (I use Woolwax). A downside of that durability is that coated surfaces are messy but a quick wipe with a rag before working on something is way better than dealing with rust.

 

[coldtaco]

Thinking of doing the same sometime this summer/early fall. I want to try the stuff at Homedepot. There’s a couple of YouTubers from the Midwest who have tested different products.

 

[kcjaz]

Thinking of doing the same sometime this summer/early fall. I want to try the stuff at Homedepot. There’s a couple of YouTubers from the Midwest who have tested different products.

There is almost too much YouTube and forum content related to undercoating. A lot of the YouTube videos I’ve found don’t impress me as conveying genuine knowledge/expertise. They tend to be just some dude with a spray can or they are trying to sell a specific product.

I think I am going to at least woolwax (seems like that is what a lot of the internet says is best for new vehicles) the inside of the box beam frame rails. I had mine up on the lift yesterday changing the oil and there is some kind of thick spray on coating on parts of the under body. It’s not universally applied. Looks like maybe on body metal seems, though I thought at least parts of the body was aluminum (the hood is for sure). Maybe I’ll do a few sports on the exterior of the frame, then drive some dirt roads and see how nasty it really is.

 

[aztoyman]

I grew up in Buffalo, NY and my fathers vehicles ALWAYS fell apart before they ever came close to wearing out. He bought his first ever new vehicle when he was 70. A 2005 Sequoia and he had it sprayed with a Lanolin or Wool Wax like product every October. He bitched about the spots on his driveway but that truck lasted him until he died at 83. My brother took the truck and never continued with the rust proofing and it had massive holes through the body panels and the frame was shot after two winters.

As a former mechanic, I can tell you I didn't like working on greasy nasty vehicles but at least I could pressure wash them before doing so. Parts are often like new under all that "gunk". Rusty stuff ends up getting disassembled with a torch. As much as I hate leaks, it can be a good thing for the rust belt.

 

[coldtaco]

I think it’s called Blaster Surface Shield that the one guy likes better than the lanolin type, it dries a little drier/harder than the lanolin, but still needs applied yearly.