The wall paper came off clean and walls were smooth except for a few nail holes. It appears that the walls had never been painted (I just bought the house). Started to prime the walls with Zinsser 123, and it started to bubble. Scraped and sanded the wall, then washed it with a solution of TSP. I am now getting additional bubbling of the primer that was left. Should I try an oil based primer after scraping/sanding? Don’t want to think about replacing the wall board, although that would be an excuse to insulate and rewire.