I am sanding my primer and there is pitting. Even after I get all of the guide coat off there are still some pits. I have sanded down to the old paint in some places and it is frustrating. The picture shows the pitting as darker spots, with more sanding done at bottom. some say it is too dry, add more reducer, some say the tip is too small and should bump to 2.0 (google) Experienced painters please help.