Are you spraying it while it is flat or hanging? For whatever reason, I have an easier time with spray paint when the body is flat and not hanging. Also, I don't wet sand during paint, I dry sand the paint until smooth every 2 or 3 coats.
A combination of flat and vertical. Kind of just depends what part of the body I'm spraying. Flat does seem easier to get an even coat but I'm also worried about spitting with the angle of the can I have to use for flat.



