If you want a nice looking paint job without too much work, you'll need a base primer and a surfacer primer.I have been using mp170 epoxy with mp175 catalyst by PPG with good reults. It sticks to anything, sprays easily, and seals out water if you don't paint right away. Then, I have been using xtreme acrylic urethane surfacer primer by 5-star with mixed results. It sprays on thick, but if you dont sand it down right away it cracks. I have also been having trouble getting it to move through the gun as it is too thick and there are no thinners/reducers listed for it.