Cleaning black streak?

[rhino_160]

My camper has the metal siding that's on most intro level campers and has the black streaks starting to form. I have used the "black streak remover" from Walmart with no luck. I've literally held a pressure washer against it with no luck. Scrubbing with a scrub brush has no luck. How can I get this stuff off??? Thanks all

[BandJCarm]

https://www.amazon.com/Meguiars-Mari...ct_top?ie=UTF8

[Gripper]

Try spray nine

[brusso]

Use the cleaner, but use a bounce drier sheet to scrub it. Just due a small area at a time. I did it on my CC Champagne and it did not harm the gel coat. Should be fine on aluminum siding. I learned it from an rv washing guy in Destin FL. He was there doing a whole rv and I had him do the bugs on my front cap. I asked him about the pad that he was using. He told me that it was a nylon pad, (a thick bounce sheet) made by 3m. And will not hurt gel coat.