sand blasting to gell coat????
If it''s cheap paint, I would think it would come off fairly easy with a paint remover. Sand blasting is not a precise removal method. If you work one spot to much trying to remove the paint you''ll end up making mini-craters with domes. A steel vessel would be the only one I''d sand blast! If the paint is peeling or flaking, try a pressure washer first, then remover, then wet-n-dry sandpaper (wet) or scotch-brite with a remover.