Best treatment for surface rust on rockers under mudguards?

The previous owner of the Battle Wagon installed Votex mudguards but underneath those the paint on the rockers is flaked off enough to leave a couple inches expose metal, which unsurprisingly now has surface rust on it. Since it is almost completely covered by the mudguards I'm not too worried about what it looks like but I want to make sure to stop the rust in it's tracks so it doesn't get any worse.

I don't have a lot of experience in this area myself. Anybody able to recommend the best rust product for this application? POR15 seems an obvious choice but it sounds like a pain in the ass to work with and paint over (which would be required since it is UV sensitive and the sun will get at least the edges of it). Anything else?

Or am I overthinking this and am I better off to just go get a can of rust primer and some colour-matched paint?

I feel your pain. My Jetta is starting to show rust around the same spot, and also on the arches of the quarter panels. I figure I'm just going to grab a replacement panel and repaint it, and then sand off the rust/paint/prime the rockers.

Hopefully the rust isn't too bad, but if it is I guess I'll just have to pony up for some new rockers. That little gap behind the mudflap/wheelwell is s death sentence to the rockers imo.

I've used RustBullet (sold by Summit Racing) for years on Mk. II's and now Mk. IV. Really needs to be applied to bare metal. Not a quick-and-easy like you want.

Prairieview said:

I've used RustBullet (sold by Summit Racing) for years on Mk. II's and now Mk. IV. Really needs to be applied to bare metal. Not a quick-and-easy like you want.

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I'm not necessarily looking for quick and easy, but reliable and straightforward to use. POR15 for example, seems to be hit and miss even for people claiming to follow instructions to the letter. And there is also some disagreement on how to apply paint to it (best to apply while tacky or wait until dry and sand first? do I need to buy the Tie Coat primer?). It just doesn't seem as idiot-proof as I'd like, but if it is clearly the best product for the job I'll give it a go. I actually do have an unopened POR15 starter kit on-hand to use.

Rustoleum. Used that on my pickup, rust hasn't come back yet after 3 years.

In the mean time u could apply some phosphoric acid and it will convert the rust to iron phosphate. The iron phosphate will be black and protect against more rust. Just be careful and not get it onto painted areas. It's the same chemical por 15 uses to prep the surface.

I just had my mechanic pull the front fenders and clean up the rocker rust. Moisture collects on the top of the rockers and can make holes in it, causing it to rust from the inside out. If you want to hold off rust repair I'd suggest you pull the fenders and use epoxy or similar on the tops of the rockers to keep the moisture out. Then paint with POR-15 or something else: I agree that feedback on POR-15 is mixed here. But I'm not sure what would be a better option.

The important thing with rust is what you see is usually only a fraction of what's there.

Plus, the sum***** never sleeps......
(I'm laughing...but, it ain't funny!!!!)

POR 15 did not save my right fender nor the front of the hood.

I have not had good luck with por15.


Regardless what they say, you CANNOT paint over rust, it will continue to grow underneath. Problem with rust is it drills into the base material and unless you sandblast it off or completely cut it out, it will come back over and over again.

Nero---Rustoleum. Used that on my pickup, rust hasn't come back yet after 3 years., which one? They make a few. You mean a rust converter from Rustoleum?

VincenzaV said:

Nero---Rustoleum. Used that on my pickup, rust hasn't come back yet after 3 years., which one? They make a few. You mean a rust converter from Rustoleum?

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Yep that's the one. Don't think I have the can anymore, but it was clay in color, just used that on the underside of the bed and it's been that way since.

I've used Rustoleum about 8 years ago on my 89 Suzuki motorcycle when I first got it in an effort to redo the frame. Used a wire brush to get as much loose crap off as possible and then cleaned it up before spraying it on.

Been good ever since. Not sure if it was a rust converter or not, but it said I could use it to "paint right over rust" so I assume it probably was.

I have used Plasticote rust converter with pretty good results over the years.
Follow directions.

Anybody ever use BlackStar?


Thinking of giving it a try this summer. It also comes in an aerosol.



http://www.mrochem.com/BlackStar-Rust-Converter.html

I will second IBW. if you see rust behind the mud flap there is probably more in behind. I’d pull the fender liners and look at the seam between the fender and body. Clean out the salty wet mud. Shooting a pressure nozzle in along the top of the rocker panel with the door open is supposed to keep it clean behind the liner - if done often enough.