Rocker panel paint for my forever truck.

[jjeff]

So after much personal debate I'm keeping my GMC 2016 3/4 ton. rocker panels are just starting to show failing bubbling paint and a few ew small rust streaks familiar using with a hvlp sprayer or brush rust oleum primer first than paint it. Thinking of using a bed liner this time rockers would end up black textured kind of matching black plastic wheel well liners. Current GMC paint on rockers was textured color matched from new anyway. Cab corners are still in decent condition rockers have no rust perforation yet to my knowledge. I'm sure if I do nothing before this winter they will be completely trashed. Plan is to strip current rocker paint on truck to bare metal. Using a wire cup brush and similar. Tape bottom of doors, fenders, and box corners blow dust off wipe clean with acetone possibly rough up bare steel with sand paper then use spray on bedliner on rockers hopefully I won't have to use bondo. Id probably use a marine based filling, fairing compound compound two part epoxy it's called vc watertight and doesn't absorb moisture. It's pricer than regular bondo but works good considering it's designed to be used underwater and hardens solid yet still sandable Definitely not a pro body tech. My question is if a black spray on bedliner is used would someone with more experience than me use an etching primer first before bed liner or any primer first Can if I'm feeling real creative color match paint over the black truck bed liner? Probably won't just leave it textured black. But I know something needs to be done now vs later. Thanks, Expertise and suggestions are appreciated. Pics available later today if needed.

 

[WinterDeere]

Don't rockers usually rust from inside-out? Every time I've ever thought I might have stopped body rust, working from the outside, I find it always continues or returns from the inaccessible back-side. Short of cutting the whole area out and welding in new, I don't think you can ever stop it.

 

[Shawn T. W.]

I'm not expert ... But ...

I'd think POR-15 1st, then cover with bed liner

 

[jjeff]

Don't rockers usually rust from inside-out? Every time I've ever thought I might have stopped body rust, working from the outside, I find it always continues or returns from the inaccessible back-side. Short of cutting the whole area out and welding in new, I don't think you can ever stop it.

I'll see where and how it started once I get the paint off.and see if any area is perforated. I think replacement rockers with out cab corners are 3-400 bucks a set if I need to do it that way. rockers were textured like that since new from gm. I'm surprised they lasted as long as they have if bare metal is on the back side. Hoping it's caused by moisture trapped between the textured paint and rocker.

 

[dodge man]

Let it rust. There is almost a 100% chance it’s rusting from the inside out. I’ve battled rust before, it’s a constant battle. Unless it’s a classic car or truck worth a lot of money it’s not worth it.

 

[jjeff]

To Stubborn if I can make a somewhat legitimate worthwhile effort to curb rust I will at least try to. I'm assuming the rockers are bolt on where? Idk Like I said not a body shop tech. . I think moisture was definitely trapped between the paint and rockers causing it to blister and bubble.

 

[Snobdds]

That body mount is what the inside of the rocker looks like.

It's already gone. Just pay the man to put new rockers on if you plan on keeping it. Do it while they have something to bond it too.

 

[JTKub]

At best you may be able to slow down what you have going on there by sanding, filling and painting, but it's not going to stop.

I don't know how these rockers are constructed and attached to the vehicle, but I've been treating my vehicles with fluid film and/or woolwax for years. If you can get this type of product sprayed into all the voids of the rockers, it will prevent this, or at least slow it down to the point other things are going to fail before the body/frame does.

I buy these products by the 1 or 5 gal pail and have several different spray gun kits, with the wands, etc. It's all a product of living in the Buffalo NY area.

 

[Midniteoyl]

If its not that bad, you can strip the rockers and and use some Kleen Strip Concrete and Metal Prep (phosphoric acid) over the wire brushed rust to convert it to Iron Phosphate (ie: rust converter). If its not that bad and if you can drill a few holes on the back or underside, you can spray it liberally up inside to convert what you can, then follow up with something like Blaster Surface Shield sprayed in after it all dries.

I use the Kleen Strip all the time on things like trailers and outdoor equipment. Works great. You can dilute it as needed and there are formulations listed on the bottle as well as the web. Can also be used to clean Aluminum, but dont let it set very long or it *will* etch it.. Made that mistake once

Heres a little vid, but this guy had to replace the rockers. He also uses a cheap electric HVLP to spray the paint after.

Kleen Strip Concrete and Metal Prep: Klean-Strip 1 Gal. Concrete Etch, Metal Prep and Rust Inhibitor Outdoor Cleaner GKPA30220 - The Home Depot

Blaster Surface Shield: Blaster 12 oz. Long-Lasting Surface Shield Rust and Corrosion Protectant, Lubricant Spray 16-SS - The Home Depot

 

[dodge man]

The rockers are welded in, not bolted. I’ve been down this road multiple times. Rust is like the proverbial ice burg, what you see is just the tip of it. You can’t do anything to stop it except cut it out and replace it. After that it will pop out again somewhere else, usually above the rear wheels, then your tailgate, then the cab corners, then the fenders, you get the idea.

I’m not trying to discourage you, it’s a battle you can win, it’s just expensive. In the end it’s not financially advisable to fight it. You’ll pour money into it you’ll never get back.

I’ve been into classic cars. If that was a 70 Hemi Cuda I’d laugh and tell you that’s not rusty. I’d say that because the car would be worth over $100,000 and worth every penny you sink into it. With your truck, not the case.