paint bottom

Need some advice. My cat 22 has vc17 on the bottom and seems to have many layers of paint, it is also flaking/pitting in places. I’ve been sanding for hours with wet 60 grit paper which is very slow going, acetone didn’t seem to do much other than smear it. I see gel coat in places and what I...

I'm finishing up sanding my bottom but the keel had some blisters and I sanded down to bare metal. Any recommendations for a rust inhibitor/primer? plan to put on a gel coat next.