Sanding paint/gelcoat help needed

[simon656]

Hi guys, undertaking a full refurb of my tub and wondering about the grit grades I should be using. It has been painted 3 times by the looks, 3 top coats and 3 primer coats. The big question is how I can pull it back to original gelcoat efficiently without doing damage. Have started with festool orbital starting with 80 grit to burn through the paint and once gelcoat just starts showing I switch to 100 or 120 . Is this ok or to heavy, have learnt it's going to take some serious time.

[FishHunter]

soda blasting is the only way, sand paper will break through the corners and edges quicker than the flat areas and 80 grit will leave such deep guoges you may never get them out before you hit glass.