Are All Undercoats Created Equal?

There are several good products. I have used Amsoil's Heavy Duty Metal Protector as an "undercoating". Apply annually. No build up, does not attract dirt / dust, etc. Aerosol can with straw for getting into all those tight little places. I even use it with good results on my heavy commercial trucks that live in the rust belt and operate in that slop all winter long.

The only "undercoating" I would consider is a product called "Mouse Free".

http://www.mouse-free.com

Been using Fluid Film for 3 years. Very good performance on a vehicle known and in some states recalled for frame rust . (toyota tacoma) Also use it on my Class C underbody. I think it is necessary in the rust belt areas. I have seen too much rust out failure of cars and trucks. Even thinking about doing it as a side job in retirement to earn some extra money. It is a very effective product from my experience.

Lizard skin came into my knowledge when I watched or read an account of building Mustangs with 427 engines and larger, Eleanor, very high dollar cars.
Metal they use today is more resistant tor rust but.....
Traditional asphalt undercoating, as noted by others, does let moisture get through and comes apart and falls off from it, and grit and rocks and so on.

Hopefully you realize that undercoating and rustproofing are two different things.

Undercoating is a thicker product and is for sound deadening. Rustproofing is a thinner product and migrates into nooks and crannies for preventing rust.

I had my truck Ziebarted when new last year. I bought the 2016 when the frame of my 1998 rusted thru.

Rustproofing also helps with things like brake lines. The (non-rustproofed) 1998 was on its third set of brake lines.

Thanks to everyone who responded. I can tell that I am out of the loop when it comes to undercoating. I DO APPRECIATE the input!

All vehicle mfg has that warranty policy however all the trucks warranty (engine/drivetrain/other/etc) isn't voided.

before you do it you might check with ford. i was going to do my buick enclave and buick said i would void the warranty if i did.

Check with the better paint and auto supply shops. On they were using some time ago was called Lizard skin. It not only protected the metal it deadened sound a bit. I think it was urethane. On dry metal once on water can't get to it.
The old tar like undercoatings invariably came off the very area attacked the worse by slat, grit and slush. Of course anywhere near an ocean metal rust very very quickly. I would think the truck bed coatings would be outstanding.
Prep of the surface is vital. One reason to do any coating right o the showroom floor or before any moisture or dirt gets to it.

SidecarFlip wrote:

NHIrish wrote:
Take a look at fluid film. I use it on my trailer frame and truck frame. Apply it annually. The best bet is to buy the spray gun kit for your compressor and spray once a year. It is a lanolin based product and it works well...and you can use it over existing rust.
Should you not be the type that likes to crawl around on the ground, you can go to their website and find a local automotive sprayer.

+1. Been using it for years. My 1997 F350 attests to it's quality. No rust anywhere up here in the corrosion state...

+2. I first found this in the marine industry, used to prevent corrosion on boats in salt water. I spray it inside the frames and all the underbody crevices. It does smell for while.

I have seen some parts "undercoated" with an epoxy spray like a truck bed liner. This is useful for wheel wells because it helps mitigate damage done by a blowout. For other parts underneath, I'll leave that up to people that know what they are doing.