Are All Undercoats Created Equal?

You want the best?

This is what I used when I did autobody work.

3M was the best. I tried other brands but always came back. It always went on so nice and smooth. It always had the perfect pattern. Always warm the can up in warm water before you start and it will come out like factory.

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...

cars are dipped at the factory to stop corrosion.
Some folks like myself undercoat a vehicle to cut down or eliminate on road noise. And they rust out also as evident of all the later model cars/trucks from up north.

Years ago asphalt based undercoating was used. This stuff would hold moisture.
I like the newer rubber based products as they don't hold moisture.

I had a '90 2500 chevy undercoated with the then new rubber based product. Kept the truck for 235k miles and 17 years then sold it. The old truck is still in the area with 380k miles ....and no rust issues....just the OEM paint coming off in spots as many 'late '80s and early '90s era GM trucks did.

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.

You should know what coating has been applied from the factory. AFAIK, all car frames and bodies are now "dipped" in an electrolytic processed primer before any top coats are applied. Choose a top coating that is compatible with what is on the surface of what is to be painted.

One of the better coating products I've used on vehicles is 3M textured rocker panel spray. In the 80's and 90's a lot of cars had this textured coating to keep road abrasion from the lower parts of the car. The car body was primed, the 3M spray applied, and then the top coats of paint applied.

mikeleblanc413 wrote:
We have purchased a 2018 Ford Escape and want to do the undercoating ourselves. There are many suppliers of the product for a do it yourselfer. Looking for the best product for the money. What is your experience with any of what is available?

I used some kind of spray can from Canadian tire store,,cost about 10$,,takes several to do truck frame and door cavities.

I think its same stuff most garages use,,last for a while..but I always get under the truck once a year and touch up whatever comes lose..
Also tried truck bed box coating on inside fenders this year,will see how long that last..

One time I bought old Monte carlo that first owner undercoated with some black hard shiny looking stuff,,not sure what it was though,looked hard and shiny like epoxy ..couldnt even scratch it,,

Most important is to wash and clean underside of the vehicle real good and make sure its dry,before painting it..not much fun but worth it if you like to keep it for long time,,my trucks is 9 years old and still
Solid..

Have steel wheels and those have started rusting because rain water sits inside the edge of it and doesnt flow out until you drive..
I used POR15 and bright aluminum over that,,
If there is any rust,,you should use Rust converter primer first..

GordonThree wrote:
Is it even necessary with the aluminum unibody and sub frame most light vehicles have?

I doubt everything in a car body and suspensions is aluminum..
Touching it with magnet would be one way to find out..

Also Ive seen some aluminum wheels pitted and worn out looking,not sure if its from road salt or what..

Is it even necessary with the aluminum unibody and sub frame most light vehicles have?

IMO the only time to undercoat something, which is pretty much totally unnecessary these days, is before it has ever turned a wheel on the road. Personally I've never undercoated a car and never regretted it. Just one more way to transfer those green bills from your hand to theirs.

mikeleblanc413 wrote:
We have purchased a 2018 Ford Escape and want to do the undercoating ourselves. There are many suppliers of the product for a do it yourselfer. Looking for the best product for the money. What is your experience with any of what is available?

i haven’t heard of a vehicle needing undercoating in, well, years. i think the last new car we had undercoated was a 1970 Ford Maverick or maybe our ‘73 Pinto. is undercoating really necessary?