ppg dp40 gray green or 90 black or 60 red they make more but the 90 maybe what you want this will do a good job of sealing and when ready to paint wet sand out with 3m gray back 320 paper with ppg 330 wax and grease remover this keeps the paper from plugging up.put the 330 in a spray bottle this works good .you can use a red 3m scrub pad i do both and then reseal or prime up