Under body treatment

[DanC]

What do most builders do about coating/painting the underbody of the roadster?

[Papa]

I used Herculiner roll-on bed liner.

https://www.amazon.com/gp/product/B0002TDUW4/ref=oh_aui_search_asin_title?ie=UTF8&psc=1

Others have used a similar product from Duplicolor.

https://www.amazon.com/Dupli-Color-BAK2010-Armor-Truck-Kevlar/dp/B003E21QM2/ref=sr_1_2?keywords=duplicolor+bedliner&qid=1550245051&s=automotive&sr=1-2

Dave

[DadofThree]

Others have used a similar product from Duplicolor.

https://www.amazon.com/Dupli-Color-BAK2010-Armor-Truck-Kevlar/dp/B003E21QM2/ref=sr_1_2?keywords=duplicolor+bedliner&qid=1550245051&s=automotive&sr=1-2

Dave

This is the one I used per recommendation of Jeff Kleiner. Water based for easy cleanup.

[Jeff Kleiner]

Herculiner, Bed Armor, rubberized undercoating or nothing at all. Some owners do it themselves, others have me do it when I paint the car.

Jeff

[GoDadGo]

Raptor Bed Liner In Red To Match The Color Of The Car!

U-Pol Raptor Blood Red Urethane Spray-On Truck Bed Liner Kit w/Free Spray Gun, 4 Liters

[BadAsp427]

Herculiner, Bed Armor, rubberized undercoating or nothing at all. Some owners do it themselves, others have me do it when I paint the car.

Jeff

I followed the lead from one of the best, Jeff K.... Very easy to use, clean up and very very low odor.
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[dbo_texas]

What is the benefit of covering the underside? Is it cosmetic only or are there concerns with rocks/debris hitting the underside of the body and causing damage? I know people apply this but wasn't quite sure why.

[Papa]

What is the benefit of covering the underside? Is it cosmetic only or are there concerns with rocks/debris hitting the underside of the body and causing damage? I know people apply this but wasn't quite sure why.

Purely cosmetic in my opinion. I didn't want to see red, unfinished fiberglass from the underside of a blue car.

[DadofThree]

What is the benefit of covering the underside? Is it cosmetic only or are there concerns with rocks/debris hitting the underside of the body and causing damage? I know people apply this but wasn't quite sure why.

My reasons were a little of both.

I wasn't going to paint the underside completely, but instead just hit the wheel wells heavy. But later I learned from Kleiner that painting the entire underside helps its appearance when you see it as you open the hood, or trunk, etc. He was right that it made a positive difference in appearance. No more seams in view. As for the wheel wells, I ended up going VERY heavy in there to help provide some rock cushion/protection. I did many layers in the wheel wells and even went as far as pouring it in that area before spreading out.

Let it bake in the hot sun for hours, and you're good.



https://farm1.staticflickr.com/959/27899072018_180b6e1cc1.jpg (https://flic.kr/p/Jvm385)20180428_092323 (https://flic.kr/p/Jvm385) by D. R. (https://www.flickr.com/photos/annabellerose/), on Flickr


https://farm1.staticflickr.com/903/27899080348_8988322168.jpg (https://flic.kr/p/Jvm5AG)20180428_121046 (https://flic.kr/p/Jvm5AG) by D. R. (https://www.flickr.com/photos/annabellerose/), on Flickr

[Gumball]

Okay, so I'm going to come across as more than a little OCD with this reply. I did coat the wheel well area with bed liner (just the fiberglass - not the aluminum panels), but the rest of the interior surface was smoothed with slick sand and sanding, then I applied an aluminum appearance paint (Eastwood Alum-a-Blast) using a dry brush technique, in order to replicate the appearance of mill-finished aluminum.

I even went so far so as to put in a bunch of 1/4 moon shaped divots using a small sanding disk so that it would look like hammer marks.

Most of the inside of the body isn't visible once done, but there are some spots that you can see, like inside the engine bay near the footboxes and near the door hinges.

Here's a shot of the rear passenger side wheelwell area before I applied the bed liner - since this was covered with bed liner, I hadn't smoothed the fiberglass as much as I did in the visible areas.

https://i845.photobucket.com/albums/ab15/CCRsAC/IMG_20140911_215210703_zpsoon3hiba.jpg (https://s845.photobucket.com/user/CCRsAC/media/IMG_20140911_215210703_zpsoon3hiba.jpg.html)

[Ray]

What is the benefit of covering the underside? Is it cosmetic only or are there concerns with rocks/debris hitting the underside of the body and causing damage? I know people apply this but wasn't quite sure why.

I wanted to seal the underside of the body against moisture and also re-enforce it from rock strikes. I've seen a couple of cars that had star cracks on the nose from rocks that bounced off the radiator and hit the underside of the nose. Not saying that the undercoating will stop all of that, but it won't hurt.

Ray

[daltmcintyre]

Are any of the undercoatings able to be painted? I’d like to follow Chris’s lead and undercoat, then paint to look like aluminum

[Scott Zackowski]

I went with Rust-Oleum Truck Bed Liner and have been pleased to date.

I coated the entire underside of the body and plan to add extra coats to the wheel wheels. It went on easy and dried fast. Based on my research it is a little thinner than some of the other bed liners mentioned, which worked well for coating the fiberglass and providing a smoother finish. For a truck bed would probably want a thicker product.

[Mark Eaton]

I am planning to use on of the spray on products and I will go ahead and do my truck bed at the same time. I have read in other posts that it not only protects the body but does add a "solid" feel to the car and may reduce road noise...

Mark

[AC Bill]

I painted the underside with black epoxy paint, to seal it. I later applied undercoating, to the wheel wells.

[swwebb]

I added wheel well liners from Alex Dailey

http://acroadsterinteriors.com/Fenderliners.html

to hopefully avoid star cracks from rocks being thrown up by the tires.

I'm also considering spats on the rear fenders to help protect against rocks from the tires. After about 6000 miles, I have one chip on the driver's side rear fender from a rock (probably).