I have painted two metal flake boats and I used Deltron (PPG) on one and Imron (Dupont) on the other, the metal flake is porous so it needs to be super clean, steam works killer, but be prepaired to deal with some imperfections, you can DA or block sand the flake smooth then spray a good filling primer, the product I like the best so far is from Evercoat Marine coatings (same Evercoat as automotive, but auto paint stores dont carry it) its called CoVall, basically a high filler polyesther based primer that blocks out really easy. after its primed and blocked (several times if you want it really flat) you can pretty much seal it and paint it with whatever, but dont recommend basecoat clearcoat below the water line.
For my next boat (White Trash II) I plan to use the primer/filler from Duratek, I have been told that this is the shizzle, the boat will be painted in Duratek mold paint, we'll see. Hope this was helpful.
