I have found some really great primer in a spray can that, to me,
is comparable to K-36. So if you don't want to haul out the spray
equipment every time for primer this could be the ticket.
It has great adhesion, coverage and sands and feathers as good as the PPG.
Find it at paint and body shop supply stores. Kind of expensive @ 11 bucks,
but the ease of use is worth it.