Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Cleaning Brownish (rust?) off exterior paint

I’m not sure if it would be rust, because it’s on the outside of the car, where there is paint. I tried Goo Off, but it didn’t get it any cleaner. Any advice about how to remove the Brown would be much appreciated. See photos below. I included a photo of the rear door as well for comparison. Thanks!

That’s what’s called surface rust. If left alone it will eat through the metal. A Brillo pad will take the rust off and make it look better but it needs to be attended to. Best is to sand it, use a rust converter and a rust coating (or epoxy primer) and repaint. At least clean it off and put a rust converter on it before it gets any worse.

I’m not sure it even is rust. It appears to be on the body side molding which is almost always plastic. What happens is the special finish on these wears off and exposes the plastic that the molding is made of which then deteriorates.

I guess I didn’t look at the picture close enough. I thought it was a lower door panel and not a molding. Sure looks like rust though. A Brillo pad will still take it off easily but will scratch the surface some. Actually aggressive rubbing with wax will remove it too or any of the products for rust stains like CLR will remove the stains. Then wax or refinishing should keep it looking better.


I might try a Mr. Clean magic eraser on it, very carefully.

This may not apply to your vehicle OP, but my truck has a piece of chrome anti-ding molding running horizontally down each side, and rain water tends to accumulate there and cause an annoying band of surface rust at the bottom edge. I tried various methods, polishing compound and sponge, steel wool, or just wax, all worked but the rust would eventually return. The best result I could get was to remove the rust then apply a generous band of wax there. That would keep the rust at bay for a couple of years at least.

Finally I decided to remove the trim and take a look underneath. Sure enough, the trim popped right off and it was like a rust farm under there. Once I got rid of that under-trim rust the problem hasn’t returned. So if that is a trim piece I’m seeing and is easily removed, suggest you try that.

I first thought “rust” and then enlarged the photo and thought “nope”… but I have no other answer. If the trimpiece is metal, it’d be worth it to try to remove it. If not, I’d suspect a mounting tape adhesive failure. You should be able to tell by tapping it lightly with a screwdriver handle or something similar.

NOTE: nylon auto body pry levers would be an excellent investment… and they’re dirt cheap. They can be used to remove the trim without damaging the paint or the body panel.

Thanks for all the advice. The part in question is the door bumper guard.

Strange that the bumper guard can get rust being that it’s plastic? no? Sure as hell looks like rust to me though : ( I did see that I could buy a new set of bumper guards for $100, but I don’t really need all 4 replaced and its not like it looks all that bad. I’m thinking that I’ll try to pop it off and wax the hell out of it, to start.

Any recommendations for wax to use? I’m on a budget. Thank you all!!

Try cleaning it with some sort of brand name body finish cleaner. There are lots of them on the shelves at a car parts store or a big box retailer. If it’s just unexplained filth, it should come off and not present a problem.

I found that it can be hard to get into narrow spaces to clean this kind of glop out, so I wear a latex glove and rub the cleaning material on with a finger tip.