Matrix makes a good epoxy primer. Just used it as a final prime/sealer for my W350. Filled 150 grit with 2 medium coats. It sprays with alot of peel if you reduce per the directions, but reducing 4:1:2 instead of 4:1:1 made it lay down like glass. Wet sands pretty well also. I paid $125 a gallon with the hardener.