First let me apologize, as I know this has been asked before. I just can't find the answer. I have primed (zinssers 123) the ceiling in two rooms. First room is still showing a dull beige look. I also stripped the trim to bare wood, then primed. It also has a brownish color. The trim is old , (100 yrs) prob yellow pine, at least looks like it. Is there a good rule as to know when to double prim, or you just kinda know? I don't want to add work, but don't want bleed thru. Topcoat is val spar on ceiling and benj moore regal on trim.