Slick sand is not a high build primer, it is a sprayable body filler. Yes, porous like body filler. I use a couple coats of Epoxy primer on the bare metal, let flash and spray slick sand, let cure and then sand DRY. Spray the SS again (as needed) and sand again DRY. Once "straight", cover in epoxy as your sealer, and wet sand that. (when using sandable epoxies, H/K or SPI, etc.)
Slick sand requires an appropriate gun for spraying, mine has a 2.5 tip. If you don't have the correct spray gun/tip, you are defeating the purpose.
