I have all the paint removed from my old Keith Steele boat except for a few areas where the paint is so deeply embedded in the grain that it seems more like stain, Doe anyone have a secret that I should know for getting that out so I can apply a clear finish? Here is what I have tried so far:

Sanding (and sanding and sanding and sanding) From 40 grit on a belt sander to 150 by hand.

Heat gun.

Bleach (followed by sandiing)

Paint stripper (followed by sanding)