F451

Hey guys,

Does anyone have any advise for removing stubborn black road tar & debris from the underside of my '88 928 S4?

The single stage indischrot red paint has 32 years of abuse showing, particularly on the underside. I can't get these black stains off the paint. I assumed bug and tar remover would do the trick and get the majority of it off, but it barely put a dent in it. I applied it with a microfiber towel, let it soak for a minute or two, then gently rubbed it, re-applied a number of times. Followed that up with car wash soap and a good rinse to remove the chemicals. That process managed to get some of it off, but as you can see, the stains are still there.

It feels like its on top of the paint, and not actually in the paint if that makes sense. I can feel the texture when I run my fingers over it with thin latex gloves on.

I don't want to get too aggressive so I'm not sure what to try next. I'm assuming a clay bar won't do it, but may give that a try this morning just for the hell of it.

Any tips or advice on how to deal with this would be greatly appreciated.

Thanks. -Ed

Marine Blue

Initially I would try Clay Bar as it is designed to remove surface contaminants. If that fails your next step would be a mild polish like Meguiars 205 and a finishing pad. Polishing will remove some of the paint but it will also remove embedded contaminants. Be careful around the edges of the plastic as the paint is usually much thinner and you can wear through easily .

DreamCarrera

Have you tried a degreaser? I like P21S Total Auto Wash. It is clear coat safe but check to make sure it is safe for your single stage paint if you decide to go this route.

F451

Thanks, I think you're correct. I'm planning on polishing the entire car soon, so will see about using a more aggressive polish on those lower areas. If I can't remove it with the polish, I'll just leave it for now. I really don't want to remove any more of the paint then I have to. If I can get it "less obvious to see", I will be happy with that for now.

F451

Yes, thanks. I've tried all the usual cleaners. Started with a good wash, then Simple Green, then degreasers. Then moved on to what I thought was pretty aggressive with the bug & tar remover. All those efforts just removed the bulk of it that was obviously raised on the paint.

Fortunately, so far, those efforts do not seem to be removing much paint, not seeing any substantial paint coming off on the microfiber towels. Next up is polishing like Marine Blue suggested. But as I mentioned, if I can't remove it with light polishing, I will just live with it until I can get a professional to deal with it.

DreamCarrera

If the contaminants are sitting on top of the paint, careful work with a clay bar may give you good results.