[JoonHoss]

JMHO, they came from the factory body matching color.

If you want it original, paint them the same as the tub.

Now then, that said, I did all mine in undercoating (black) for a few reasons

1. They disappear, visually. No attention drawn to them if dirty, chipped, etc.

2. Easy to clean and maintain. I always just sprayed the underside with clear gard, tire shine, or straight up vegetable oil from my wife's pampered chef pump when she wasn't looking. Made the whole underside shine, and next clean up a breeze

3. Chips didn't happen, and didn't matter if they did. Because;

4. Easy to touch up and recoat

Hoss

 

[254Triple]

On my new tub, I went with POR15 and could not be happier. It is a bit pricey. I did the entire underside of tub and frame with the POR15 and used about 2.5 quarts out of the gallon I bought. I brushed and rolled it on but you can spray it if you have the right breather and overlay jumpsuit. You DO NOT want to breath that stuff if you spray it and a standard Covid mask does not cut it. It dries self leveling, glossy and is like rockhard. I have about 300 miles on the Jeep now from rebuild and no chips/flaking yet.

 

[JEEPFELLER]

Undercoat!!!!

Rust inhibitor!

Dampens the sound of rocks! (cake it on in the fender wells!)

EZ to touch up---if need be!

I also incorporated the "FLAT Black Paint" intp the interior of Mr.Jeep

He has a black top/ black seats/ black bumpers/ black underside/ black wiper arms/ black lug nuts

I reckon my paint scheme is two-tone Caramel over cream (the cream was

supposed to be sandstone-I'll do it correct next paint job) and Black!

You can quickly make the interior perfect in minutes with a rattle can!

------JEEPFELLER

 

[DouggetCJ7]

I cleaned mine with wire wheels and scrapers. Then painted with a couple light coats to rustoleum gray primer. Then spray can bed liner…. I think that was rustoleum too.

 

[JEEPFELLER]

bob4703s new body does tricks like yours!

------JEEPFELLER

 

[BagusJeep]

It depends on where you live.

If you live around salt then you will get corrosion, this is the top Jeep killer.

I scrape them clean, apply rust converter to any surface rust, a water dispersant if inside a cavity, a red oxide primer to any bare metal and then 2 layers of Dinitrol, a thin one and then a thicker one. The surface tension on the Dinitrol draws it into crevices, the second layer makes sure it is over all edges. It remains softish so small chips do not bother it.

If you want backup, particularly in cavities, I follow up with Waxoyl. This stuff has waxes but has white sprit as a solvent. it does not really set, and on hot days can drip out of the drain holes. Imagine where water settles, this stuff is going there.

This is not a sacrificial coating, it encapsulates the panel or section so that air does not get to the metal. Rust is ferrous oxide.

I have not seen any chipping or peeling or rust creep under the edges.

 

[keith460]

I had my painter apply factory colored Chip Guard to the underside, fenders and rear wheel wells. Its been on since 2010 and no chips that I could find.
Prep work is everything though. They sprayed over etching primer and seam sealer.

It seems I do not have a photo of the Chip Guard paint to show, sorry.

Edit: found a photo of fender that shows the applied chip guard.

 

[bob4703]

My old tub bottom was covered in rust and colored pink by southern red clay mud. The underside and firewall of new FG tub came painted black so I'm leaving it. If it don't show who GAS.

 

[Neuner-9R]

I'm wishing I had the sound deadening undercoat that was mentioned. I haven't tried POR15 and it sounds great.

What I used was High Heat BBQ Black from Rust-Oleum. Why? I had just got done painting my grill and I could not get the stuff off my brushes or hands, even with thinner. It was like a thinned tar. I thought, I want that on my Jeep!

I didn't do a body-off project, I just coat everything underneath as parts are repaired or replaced. Axles, Under-side as tranny or engine removed, wheel wells, etc. It's been over 10 years since I 1st used it and those areas still look great. No rust or chips.

I painted the rest of the jeep with it as well only as a temporary measure until I figured out what I wanted to do. Held up in the Texas sun for over 6 years at which time a professional painter said it had turned into a great primer.

 

[Rkuehljr]

On my Repli-Tub, I had it media blasted, then etch primer, urethane primer, Lizard Skin sound deadener and thermal control, and then color matched Raptor Liner. I wasn’t thrilled with the color of the Raptor in the wheel wells, so I ended up spaying them with color & clear. I drove it about 6k miles this summer and I haven’t noticed any chipping. I like to think the Lizzard Skin works, but I have no hard evidence. I also sprayed 3M Cavity Wax into the reinforcement channels, tow board, windshield frame, door cavities… for some extra rust protection.

Now I’m wondering how much weight I added?

 

[JonMopar]

Like everyone else said, it depends on what you want and where you live/drive the jeep. If this Jeep will see salty action or snow, stay away from rubberized undercoating as it tends to lift (trapping moisture and salt…I’ve seen rubber peeled off to wet rusty metal underneath).

if you want ease of ownership, POR 15 or Chassis Saver… They both are incredibly tough long lasting products, way more so than your standard rustoleum or tremclad paint. If you want toughness AND originality, just spray body colour over either of these black coatings

 

[scottyDive]

this is super helpful. We are leaning to use chip guard in black for the underneath.

 

[JoonHoss]

We used a 3M product called Rocker Schutz at the body shop I worked at back in high school, it was a paintable chip guard product

https://www.3m.com/3M/en_US/p/d/b40071586/

Hoss

 

[T Hoff]

Back in '91 I used undercoating to do my fender Wells and all under the tub. Every Fall I hit the wheel Wells again but the rest of the underside is still good. High heat BBQ by Rustoleum is what I use for my '83 Arkla BBQ grill, however I don't think it is super water tight. Regular pants and por15 is good until it gets a chip. Then moisture gets under it and festers. That's why I went with rubberized undercoating, it heals

 

[JonMopar]

Im telling you guys, I’ve done a lot of frames and the (cheaper) rubber stuff peels…forms pockets that turn into water blisters that turn into nightmares. Preparation is key regardless of whatever you use

 

[254Triple]

I agree that undercoating(rubberized) is not the product to use. My jeep was originally undercoated in 1972 by original owner. That definitely contributed to serious rust out because it cracked/peeled/blistered and water stayed. The tub was garbage and frame was also heavily undercoated on outside of frame rails, but using a needle scaler for hours on hours, got all of it off, sandblasted frame and it ended up being fine. I think the frame survived being thicker steel, but that tub steel is so thin it wouldn't take long for rust to have its way.

The POR15 has not shown any signs of chip/crack etc, but if it does, I will touch it up again. I don't think anything you can put on will stop all of it.

 

[JonMopar]

Classis Saver and POR15 when done right are as hard as a rock. To chip it off, you need a hammer. I spilled some on my took car and garage floor, so this I know 🤦🏻‍♂️😂

 

[keith460]

Boiled Linseed Oil is another cheap alternative for rust prevention. You can spray it on with a garden sprayer or brush on with a paint brush. If using a garden sprayer, be quick as it will more than likely gum up the spray tip if let to sit too long.
Cleanup can be messy and the Linseed Oil takes time to dry, like weeks.
The use of Boiled Linseed Oil has been around for over a 100 years or more. Farmers use it on many tractor implements, including myself, as it keeps rust at bay. I also use it on my CJ-7 on many of the bare steel parts and the inside of the frame. No signs of rust or peeling.

 

[baldfatdad]

i did my frame, body primer with Corlar. it takes at least a week to dry. i've run the frame across rocks and it doesn't phase the stuff. its what they paint oil rigs with in the north atlantic. read about it before you buy