I am remodeling the bathroom in my 1961 house. I have gyprock lath walls that were covered with wallpaper that had been painted over. Upon removing the wallpaper there were patches of smooth paint/plaster that had orangey wallpaper glue left and parts of the wall that is powdery and white.
I've cleaned the glue off with water/baking soda, but the smooth patches don't want to come off and I'm worried that scraping will gouge the soft white parts.
Is this old paint? Some sort of veneer on the plaster?
Do I need to remove it to apply drywall mud and eventually primer and paint?
Also do I need a special primer for the soft white plaster areas?