Spent the day priming. Total fiasco. Old primer spray gun was a POS, ended up depositing a lot of the primer on the ground. Got a new one from Harbor Freight. It worked much much better but I ended up using two quarts of primer to paint about 20 ribs and the two rear spars. I did manage to get the rear spars and parts done so I can assemble those while new primer is on the way.
(Addendum. I think I put the primer on way too thick. It is very smooth, almost like enamel. I am told it is supposed to be a very thin coat.)