yes sand it dont use primer its not necessary. fusion was mostly made for plastic cuz it actually chemically bonds to the plastic but can be used for everything else too except vinyl or leather type stuff.
just make sure your surface is stripped of all oil and dirt and the temp is 70 degrees or higher. the higher the heat the faster it'll cure and the stronger it will be. use krylon clear coat 7 days after you fusion something that way its gaurenteed not to scratch easily. its not gas proof though gas will take it off only engine enamel or powdercoat stands up to gas but even then it'll still discolor so dont spill any gas!
follow the directions on the can and use very very light coats on the first couple coats then go heavy but not to where it drips.
so i dont need to primer it if i use that paint?
