This sounds like a great solution, you used on a potable water tank?
Yes, a 157 gallon glass fiber/gelcoat built in tank on my CSY 33
Took 6 weeks to complete the operation.
Small inspection ports
, had to sand bad gelcoat
away, with one hand while laying on my belly on the floor boards, then vacuum, sand more..
Slowly but surely, one little area at the time.
Then acetone wash the inside of the tank, slowly but surely.
Then start coating using brushes
"on a stick", mirrors, whatever to make sure I got every corner. Then do it again for a second coat.
6 weeks with an hour or two a day and a few days off.
(good thing I did not pay me by the hour, I would be broke)
The final result was great, no smell or taste of the water.