Re: Jeanneau Attalia
I was just through this in the spring. I only removed the loose parts of the barrier coat on the keel, visible through cracks or rust. When shining metal appears on the keel, you are done. Rinse with acetone. Then the first two layers of barrier coat. I used VC-TAR2, because I use VC 17 as fairing. Do this in sections, so that new rust does not get formed while you are working your way round. Then a good deal of West expoxy filling. Then 8 more coatings of barrier on the keel, five layers on the hull.
It sounds easy, but it is a lot of work. The look is highly rewarding, though.
Sailing in Denmark