It seems as though the ceilings in my 1940something house were "painted" with calcimine. I'm using slightly soapy warm water (sprayed on and allowed to sit for a while) to reactivate it and a scraper to remove it. Messy work.
The layer of plaster that is revealed after I remove calcimine from a section of the ceiling is very shiny. What should I do to that shiny plaster, if anything, after removing the calcimine but before I put on primer?