Road Runner Nest

I always notice car restoations show the bottom of the cars in body color,
are they or were the cars undercoated? I was thinking of having the bottom of my car blasted and wondering if I should 1.undercoat with undercoating, 2.chassis black the bottom or 3.have it painted body color.
What do you guys think?

I'd go with factory colors on the belly of the car. You can still undercoat with something like Rust X or Rust Doctor and then paint over that with the correct colors.

When being constructed, Mopars were dipped in primer and then sprayed in the spray booth, getting overspray on to the underside of the car--the "concours" OE Gold type restoration you see, where there is primer showing on the underside dusted with body color paint.

But MANY Mopars were factory undercoated (in fact, ALL the old Mopars I've owned), so they had undercoating sprayed over this primer and paint... Personally, for a car I'm going to DRIVE, undercoating is the way to go. Why worry about the bottom of the car getting chipped and dirty?

Not to mention an undercoated car is typically quieter. Imagine every stone you run across in the road bouncing off the PAINTED underside of a car that's strictly got PAINT underneath... On a gravel road that would sound like a machine gun!

I do know about the undercoating, but I have a lot of documents from the day that shows color codes for the different parts of the underbelly.

I don't want to be misleading, ALL Mopars where dusted with body color paint as I mentioned--it was a natural result of going through the paint booth.

Undercoating MAY have been optional, and was typically done on cars that were bound for snow-belt dealers. And then of course, SOME cars, such as the SS Hemi Darts and Barracudas didn't have the undercoating at all because it was just excess weight...

Thanks guys! since I am in PA I will probably put undercoating back on,They do apply a lot of salt on the roads.Not that I plan to drive it a lot in the winter,but you never know

here's an example of a mostly correctly restored underside (car itself is black)

mopar71 wrote:Thanks guys! since I am in PA I will probably put undercoating back on,They do apply a lot of salt on the roads.Not that I plan to drive it a lot in the winter,but you never know

In the FWIW department. When I moved to Indiana (thank you Air Force) in 1978 I had my '72 Roadrunner undercoated at Ziebart. They not only do the bottom exterior of the car but they do the cavities inside the doors rear quarters and a few other places. You do end up with small holes that they put plastic plugs in though.

BEST thing I ever did for the car! When I restored it there was NO, repeat NO rust on the car except for two small holes in the fender where it bolted to the rocker panel. This was due to the fender being pulled in to the point where there was no place for water to drain.

But the normal rust places were...well...rust free.

On the downside, since I wanted to paint the engine compartment and front wheel wells so I stripped the Ziebart off. Major, major nasty job. Heat gun and putty knife was the only way. I only stripped it back to the transmission mount though. Figured since Mr. Ziebart had done such a good job for 34 years, why mess with a good thing.

Even if you are not going to drive it in the winter, there is still a lot of the residue of salt and other stuff left over, even in the summer. And if you have to drive it some winter, even just a few times, I would personally recommend a Ziebart job. (FWIW I don’t get anything from them so not pushing their product for personal gain)

One thing though...the will get a lot of that black stuff in and around the areas behind the headlights, behind the fender well removable panels and a lot of other places.

But overall...IMHO it is the ONLY way to go if you want to protect it.

Thanks for the info 72rdrnner.