I need some tips on what to do with this black stuff on painted aluminum. There are black marks under the gutters. There is also a big patch of it behind a rose bush where it whacks against the house. No concentration of SH, EBC, or Krud Kutter seems to touch it. I can smear it around with a magic eraser, so it’s not in the paint, but that just makes it look like a 2 year old was finger painting. Can’t actually get it clean. A strong mix of gutter grenade takes it off, but that does weird stuff to the paint as you might imagine. It’s like axle grease!
Looks like hieroglyphics!
Seriously though, looks like greasy hand prints.
I would start with some dawn and water. Sometimes the easiest solution is the simplest.
Its not from human touch.
Its from the wind causing the bush to scrape against the siding.
No detergents will move it and neither with mild pressure.
If you want to go hands on with a magic eraser have at it. But you couldn’t pay me enough to do that.
Set expectations from the start and you can avoid these small issues.
The others look like hand smears up top. They wont come off either without hands on. Probably from cleaning out the gutters.