I was tearing off paneling in my bathroom and behind it there was an old fake tile paneling. Behind it is black paper/glue - maybe tarpaper? Anyway, its really stuck to the plaster. Is there anything good to remove it? I want to make the wall solid plaster and remove the border, Paint thinner didn't work and water sort of works. There is also tan glue mixed in that sort of dissolves when soaked with water. Howverm I can't get it to dissolve in certain areas becuase the tarpapaer covers it.
It's probably the remains of an old wall covering called congoleum. It had a finish that imitated tile. It sometimes contained asbestos too. I've never found anything that disolved it and was still safe to use inside. Anything in the way of solvents will likely soak into the plaster and make it a problem to apply a finish. A wide wallpaper scraper and plenty of elbow grease is the best I've found. Wear a respirator and keep it dampened to minimize dust.