I have nearly finished scraping and sanding away almost 50 years worth of peeling paint from my ceiling. On some areas where I was overly aggressive with the power tools I hit drywall paper, and in other ares I have gotten to various layers of paint. My house has tested negative for lead based paint, but I have no idea if any of the coats were oil based or not. Lots of additional taping and mudding over house-settling cracks and then a bunch of minor hole patching throughout the walls.

Reading around, it seems that a latex based primer makes most sense - does anyone have any specific recommendations? I have about a gallon remaining of Kilz 2 Latex, but haven't been too impressed with it generally over previous applications in other rooms.

Thanks a million.

 

If you have any torn drywall paper or exposed gypsum - those areas need to be coated with either an oil base primer or Zinnser's Gardz.
Personally I don't think much of Kilz2. It's a poor stain blocking primer and is reported to have adhesion issues. Zinnser has many good primers with their 123 being one of the better all purpose primers. There are also good primers available at your local paint store [not a big box paint dept]

Have you skim coated over the scraped paint?

 

If you worried about there being oil based paint, I would opt for an oil based primer (partial to the Zinsser brand).

 

The odds are the only rooms/ceilings that would have originally been painted with oil base enamel would be the kitchen, bath rm and laundry room. I've never heard of any issues applying latex paint directly over flat oil.
Here's a link to a sticky on how to tell if the paint is oil or latex
Is My Paint Latex Or Oil?