Chipping Black Paint on Step and Back Bumper

[huskersteffy]

Every spring I scrape / sand and then paint my back bumper (only the surface that points forward) and the front surface of the step assembly. After only a couple of months, they both end up looking like the attached pics (heavy sigh) and I'm back to square one. I assume the pock marks are from rocks / gravel that get thrown up.

Before anyone mentions surface prep, I do use an orbital sander to get things back to bare metal before applying multiple coats of Rustoleum Gloss Black.

Has anyone found a product can be painted on by a DIY'r like me that holds up better? I'm thinking of the stuff they use for truck bed liners.

[Bayner]

Truck bed liner seems like a valid choice. It's what I'll try when I get enough wear to justify it.

[WyoTom]

My son turned me to 3M rubber mastic tape. He uses it to protect his carbon mountain bike frame. Prep your surface and clean with alcohol then I used rust converter and repainted. I hit the tape with heat from a heat gun smoothing the edge of the tape and insuring a good bond.
Worked great and that was over a year ago and I drive on dirt roads often. Hope that helps.

[Viajante]

Por15 is the best I've found as far as paint is concerned. After yearly applications of Rustoleum to the axle, bumper, steps, etc I concluded that it does nothing for rust. Por15 can be messy to work with but the results are worth it.

https://por15.com/?utm_medium=adword...xoCxhQQAvD_BwE

[huskersteffy]

Thanks for the input and comments.

I think I'm gonna try some 4" wide, black Gorilla "Waterproof Patch and Seal Tape" available at Home Depot. Will report back how it holds up.

FWIW: My manual awning had a couple of rips up high where it attaches to the trailer. I ran a strip of the same stuff (white color though) along the entire awning at the top and lapped over at the front/back edges. Has held up well for 2+ years and much cheaper than new awning. Tried the clear Camco awning repair tape first: Stay away, it started coming loose in less than a week.

[Donna D.]

Rusts never sleeps. You've got to kill it, not just simply cover it up. Just because you can't see it doesn't mean it's not there.

[Great Eggstrications]

I've had good results with 3M clear protectant film. Applied it to the forward-facing surfaces on the rear bumper, the step, and the outer surfaces of the 2 tongue A-frame members. Also the insides of the wheel wells and the under-body areas rearward of the rear wheels. It has held up very well for years, even after being pelted ruthlessly with loose gravel in Alaska and the desert southwest. Used both the self-adhesive and the water/alcohol/squeegee variety of film. The clear film lets you keep an eye on what's going on underneath.

Have also been real happy with this stuff, although they really need to work on their spelling...

https://www.amazon.com/KRUD-KUTTER-M...8&sr=8-43&th=1

It sprays on as a clear liquid so you can get it into tight spots. It leaves a whitish residue so it's good for under-carriage metal, but maybe not in visible areas. I just spray it on once a year or so and don't really worry about rinsing or wiping it off and I don't apply paint over it.

I've used it on various vehicles, but have thus far not used it on the trailer where I might get overspray on the fiberglass, not being sure how it might impact the gelcoat.

Perhaps best to avoid paint-on rust inhibitors, and in particular avoid glopping on thick "undersealer" that can separate from the metal and allow moisture and the consequent corrosion to occur undetected underneath - ran into that bigly in the past, but it didn't help that that was on an elderly British car that was built before they figured out that it works really well to throw some zinc into the the mix when stamping body panels...

[oreo]

Por 15

[huskersteffy]

I like the clear 3M film idea. Is this the stuff?

https://www.amazon.com/Scotchgard-Cl...004VG8DS0?th=1

[HABBERDABBER]

A physical barrier, after you sand and prime and paint/treat the areas in your photo might be the best bet. Your notion of the tape is reasonable and worth the experiment. Try 2 layers, eh?
Weird corrosion image you provided. Is it one side only?

[Great Eggstrications]

Originally Posted by huskersteffy

I like the clear 3M film idea. Is this the stuff?

https://www.amazon.com/Scotchgard-Cl...004VG8DS0?th=1

Yeah - that's it.

When I was buying it I found an Amazon seller that offered it in a lot of different size rolls - various widths and lengths. And there was quite a disparity in the pricing between various sellers. They make 2 types - self-stickum sticky on one side (only one chance when positioning) and the kind with no adhesive that you apply using a mix of water and alcohol (and then can slide it around to position it and then squeegee it). I used the water and alcohol type on the gelcoat and the self-stickum type on the painted surfaces. Both types have stayed stuck well.

My rear bumper and the steps looked just like the OP's. I sanded the chip spots down to bare metal, cleaned it up, primed it with rust-o-leum and let it dry really well before applying the film.

[huskersteffy]

Weird corrosion image you provided. Is it one side only?

Yes. Bumper and step only get dinged up and corroded on the front side. Every other side looks fine. Assume its gravel / rocks getting thrown up on dirt roads.

[SkipperClyde]

I got a a tractor supply and purchase tractor enamel primer and paint. I also use the hardener. Vans is my preferred brand. Take it down to bare metal before priming.

[Paul Dean]

I just dealt with this 4 months ago, so too early to tell if it's a good long-term solution. I sanded, repainted with Rustoleum paint + primer combo stuff, and then applied 3M undercoating to the parts of my 5.0 frame (like that front side of the rear bumper) that were taking heavy rock chips.

I've got a couple thousand miles since then, including a fair share of dirt roads in the SW desert, and it seems to be holding up well.

Time will tell...

[ghosthunter]

I had a similar problem on my landscape trailer fenders. I sand ,primed,painted, than I install some 3m tread pads I got at the local farm Store over the fenders. No more problem.

[JohnP]

The paint on our bumper and step (forward facing) is flaking of/has some dings (it looks like the pictures of the OP).

I am trying to find a rust paint in semi-gloss black that I can brush on. Tremclad Rust Paint is out of stock at Homedepot.ca and other stores. I found a Benjamin Moore paint that is available and can be tinted black: Coronado Rust Scat Polyurethane Enamel - Semi-Gloss (https://www.benjaminmoore.com/en-ca/...nado-rust-scat).

This paint cannot be used on galvanized steel. Is the E21 (2020) chassis galvanized?

My plan for fixing the paint of the bumper is to use a wire brush, apply Rust Disolve Jelly (Rust-Oleum), lightly sand (220, 400 grain), mineral spirits to clean the surface and then brush paint (1 or 2 coats). Do I also need to put on a clear top coat? Am I missing anything else?

Thanks!

[Ron in BC]

No, the frame isn't galvanized.

I'm not sure that I'd bother with 400 grit. You want the surface to have a bit of tooth.

Unless the clear coat is harder than the paint I wouldn't bother. Just a second or third coat of black.

I don't regard the process as a permanent fix. To me it's just a routine item that I do depending on how much I drive on gravel roads.

Ron

[huskersteffy]

Update on the 3M tape solution.

We were down on the Texas gulf coast in April and camped on or right next to the Beach for about a week. HOLY COW the sea air is corrosive! Amazing that the air worked its way under the tape and I now have rust spots again. Though not as bad as before from gravel road chipping.

I think the 3M tape solution works well as long as you don't spend time right up against the ocean.

[JohnP]

Originally Posted by Ron in BC

No, the frame isn't galvanized.

I'm not sure that I'd bother with 400 grit. You want the surface to have a bit of tooth.

Unless the clear coat is harder than the paint I wouldn't bother. Just a second or third coat of black.

I don't regard the process as a permanent fix. To me it's just a routine item that I do depending on how much I drive on gravel roads.

Ron

Thanks, Ron!