Re: How to remove anti fouling paint
I'm going through the same thing right now.
I tried a 2500PSI pressure washer to no avail, it basically knocks off all the loose paint.
I then tried paint remover and a scraper with negative results, it removed the paint for the most part, but didn't touch the scratched up areas. It also took a lot of paint remover to get through to the gel coat.
I then tried the sanding method, which I found to work quite well. It is definitely the most labor intensive, but I believe it is worth the time and effort. I'm using a Dewalt orbital sander and 60-grit to cut through the paint and 220-grit to fine tune the gel coat.
I should also note that I used a dual action sander, which really cuts through the paint, but it leaves waves/grooves in the gel coat. Then you have to use the orbital sander to smooth it back out again. The orbital sander is more of a "all-in-one" process, as it takes the paint off and also preps the gel coat for either buffing or repainting.
I also trailer my boat, so I am considering three options: paint with a hard, permanent paint (non anti-fouling), re gel coat, or buff and polish original gel coat. The problem I am running into while sanding is I am finding that some places in the gel coat is thinner than others, which makes me hesitant to buff and polish original gel coat.
To summarize, I would recommend this (if you have the tools and time):
1) pressure washer to knock off loose paint and clean up the working area
2) use orbital sander with 60-grit to cut through paint, don't go too far with this because you want to leave enough gel coat for final prepping
3) same as #2 with 220-grit to final prep gel coat
4) hand sand all the small areas and be careful to follow the natural and original grooves of the gel coat
5) pressure wash final product to remove all dust and debris from sanding process
Hope this helps,
Dan