On Feb 14, 3:06*am, blueman wrote:
This is probably a really basic question.
But is there any general rule of what the final grade of sandpaper
should be for a project that you plan to prime and paint?

I have always sanded up to 220 but wonder whether that might actually be
"too fine" for paint to stick optimally.

I always sand to 150 and then prime it. Then I lightly sand the
primer with 320 before I put the paint on it.

JP