I have an old sea king hull that is 14' long. the old deck is falling apart so i took everything out. the back inside of the boat has a layer of chipping paint. it may be lead paint. the front has paint in good condition. I bought cabbalas boat liner to put inside my boat. my problem is that i can't sand the boat without ruining my sand pads. the rivets catch on the pads every time i run the orbital sander over them. what should i do?

should i use a self etch primer?

 

If you are dead set on coating the inside of the boat consult the manufacturer of the coating you bought. They'll be able to tell you what it can and can't bond to and whether or not a primer is required. 

 

You may have to use a combination of mechanical and chemical stripping to get it properly prepped. Be careful with the chemicals. 

Use a wire buffing wheel on a arbor with a drill motor in lieu of a flat sanding disk. Wash the painted area with TSP after buffing off the loose paint, rinse then let dry.

Check to see if your coating requires a primer, aluminum usually needs a oxide inhibitor for good adhesion.

Tom

I have an old aluminum riveted boat as well.  I always told myself that when it came time to strip it down, that I would sandblast it.  I think that will be most efficient and effective, both inside and out

Surface Preparation of Aluminum for Painting

 

Sand paper: 80-100 grit

Scotch-Brite Hand Pads: part # 7447

Conversion coating: acid etch primer/Alodine/Chemfilm

Paint: automotive or marine grade polyurethane

Paint & Coating Stripper: Eldorado Solutions' DoradoTM Industrial Products part # 2021 or 5051

 

Steps

010: Clean the aluminum surface with a good cleaner using Scotch-Brite Hand Pads to remove all dirt, old paint and oxide from the surface. When sanding I prefer 80-100 grit it gives better tooth and paint adhesion.  Sanding must be taken into the best previously adhered surface in order to have the new coat of paint hold properly. Start with an orbital sander; finish by hand with Scotch-Brite Hand Pads. Rinse thoroughly with clean water & let dry completely.

020: Apply a coat of acid etch primer following the mixing and application instructions to the letter.

030: Within 24 hours of applying the etch primer, apply the topcoat finish.

 

In your case use an "aluminum" wire wheel" to remove old paint or paint stripper.