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.

 

[jjeff]

Not looking to win just mitigate the damage as much as I can. With me putting a reasonable amount of my time in it. I grew up in a rust belt I've had three Tacomas bought back or frames replaced, Fortunately the cab mounts and corners are solid still. There was mud on that one cab mount not much rust that was mentioned earlier. I ran a pick in some of the rocker bubbles with streaks of rust coming thru the paint the pick didn't penetrate thru the steel. I think it's at least worth my time taking the rocker paint off and cleaning it up and putting something like bedliner on them. But I shall see I may be surprised one way or another how involved this may be once I see it stripped.

 

[Hay Dude]

Ahhh so you were going to sell me a truck with a CP-4 annnnnd rocker rust????

Con-artist



j/k

 

[jjeff]

Ahhh so you were going to sell me a truck with a CP-4 annnnnd rocker rust?

Con-artist

ill be putting over 1k miles on it
In the next few days sure hope I don't fall thru the floor boards or the cp,,4 doesn't blow.up .

 

[dodge man]

The rust is almost certainly coming from the inside out. If you just clean up the outside it will look better for a while but not long. If you’re going to do something I’d get something on the inside to slow the rust down. I wouldn’t use fluid film because that isn’t very compatible with paint. POR15 or a similar product would be best. Once you get the inside of the rocker treated then fill the outside and paint.

 

[Topzide]

You could drill holes and spray in some, Black Star - Gallon

You can spray with a garden sprayer or squirt bottle. I've used this stuff and is easy to work with and needs no top coating.

 

[jjeff]

Boy did I open a can of worms as others implied and warned, started sanding bubbling rocker panel paint and next thing you know sanders going right thru rocker and I'm I'm cutting perforated rust sections out of outer rockers on both sides especially near the back. Removed door weather seal and started sanding that rust away on door bottoms fortunately not perforated yet. The hf fastener removal tool is invaluable removing the plastic fasteners holding weather stripping in. so I'm getting it down to bare metal cutting out the rusted parts fortunately the inners seem salvageable after sanding and eventually I'll be over spraying it with rust converting/ preventive paint. Anyways this is quite the process I didn't expect I'll be covering the rockers with abs slip rockers covers you use both rivets and adhesive to attach, instead of welding patches on. Figuring the heat from even short spot welds from a mig gun might start a fire or bubble inner protective coating im planning to use. Since bottoms of doors are just starting to rust noticed only after I removed weather stripping after everything is prepped and treated I'm thinking of running a coat of bed liner on rockers bottom of doors following top of lower plastic bed corner on both sides front to back. Definitely not a body shop tech but I do want my work I'm doing to last for the foreseeable future and not look overly backwoods redneck, without completely cutting out/ removing inner and outer rockers. Surprisingly like I initially assumed both front and back cab corners are solid with little to no surface rust on either side. Will be removing perches for running boards and sanding around them next. Helpful experienced insight is greatly appreciated not involving cutting out both inner and outer rockers. Pics suck cuz I was busy cutting and sanding but can get better ones for further insightful ideas first pic is what I'm currently planning to use to treat inside and outside of rockers. Thanks and happy thanks giving.

 

[dodge man]

It sounds like you are going to put some kind of cover over them. Keep in mind it will keep rusting underneath that. From your description of the rust I seriously doubt you will stop it completely. If you do a so-so job at what you’re doing now you will get a couple of years. A good job will get you 5 or 6 years. Like I said earlier I hate to be pessimistic but I expect it’s going to pop out somewhere else on your truck separate from where your repairing now.

 

[jjeff]

Thanks for the reply and I Understand, however I spent a lot of money bullet proofing the fuel pump and front end to plow. I've read horror stories on folks that hired others to do inner and outer rocker replacement and within a few years it was rusting thru again. My solution is costing me a few hundred and my time instead of 3-5k plus I get to learn a thing or two and somewhat enjoy doing work like this when I find the time. If I get five years out of it I'll be content more than five I'll be happy provided that trucks still roadworthy. My brand new GMC half ton with a blown transmission is unfortunately a different story and I could make a 6' complaining snow drift out of that truck .

 

[jjeff]

Also the inside and outside of existing outer and inner rockers will be treated with various snake oils to help prevent or reduce further rust.

 

[jjeff]

My goal before applying various rust preventives and primers and eventually rocker slip cover is to finish cutting out rust perforations addressing inner door skins with rust converting primer and truck bed coat it where weather stripping was. Do similar with inner and outer rockers after pressure washing insides, using a blow gun, and spraying down everything liberal with acetone. Instead of using 3m double sided tape Ill Problaby use a decent polyurethane adhesive spreading it over rocker covers than attaching it to what's left of newly primed and painted existing rockers. Using rivets also. I don't mind using extra rivets provided they are spaced somewhat straight and uniformly. Everything not covered by slip covers at box corner plastic level will be scuffed and painted with truck bed coating. Both the cab and box front to back. I'm kind of hoping this will keep the truck looking presentable somewhat flowing into current metallic silver factory paint job that's in decent shape still being ten yrs old even. Further suggestions are really appreciated if my plan is ok or terrible for reasons I can't see.