Painting over cat urine stain
I'm remodeling my whole house. The new master bedroom is now what used to be two rooms. My drywall guy repaired the ceiling as needed and then skim coated the entire ceiling back smooth again and re textured. Several spots (10 - 12) about 5-6 inches in diameter are not drying out. I thought maybe my new roof had several leaks. After digging through the insulation in the attic, it appears it is cat urine. I used to have a cat that spent a lot of time up there, but it has been at least three years since any animals could have been up there. I'm now ready to paint. Is there a way to seal the ceiling so these stains won't show through the paint?