I have some serious scuffing on my car’s door sill. I bought some black xpel film to prevent this in the future, but I want to do something to prevent rust from forming underneath the film.
I bought some color matched touch up paint, but I’m wondering if I need to remove all of the paint and primer from the area. Since I don’t care how it’ll look under the film, I’d like to just rough it up with sandpaper, prime and paint it, and then slap the film on it.
The part I’m worried about is that it’s a fairly large and irregular scuffed area. Some bits are down to metal, some down to primer, and some still has the clearcoat. I can’t really mask it off and only get primer on bare metal and the original primer.
The reason I don’t want to sand it all down is that it’s a difficult area to sand. I’m worried I’ll fuck up the paint beyond the area that would be covered by the film.
Can I do it the lazy way, or should I just bite the bullet and sand down to metal?
It’s water based touch up paint if that matters.
If you’re just going to cover it and the actual paint condition won’t be visible, I would use Ospho to neutralize the rust and then do a light scuffing with sandpaper and put the film on. I would use Ospho because I’ve got some handy. Since you probably don’t, you could use some rust neutralizing rattle can primer after knocking any loose rust or other debris off.
You don’t need to remove paint down to bare metal in pretty much all but the most detailed, show-car level paintjobs. If you were trying to paint match and not planning to use the film, you would just need to sand until there’s no visible rust and the shine has been taken off the undamaged paint, then use a filler primer to level out the area, then light sanding, then proceed with color and then clear.