Hello, Getting ready to paint the roof of my car. Rain gutter seems to always be an issue with rust buried under paint and primer from previous owners. I grinded out the rust and paint and primer down to the bare metal because I do not want to start having issues with the new paint. What should I seal that interior with so water will just fly down there and not get to the seam where the roof sits. Did the manufacturer use a seam sealer there and how did they get it smooth to accept the primer and paint.
