Our house is 50 years old. The drywall tape shows through layers & layers of paint. My husband removed the "popcorn" ceiling treatment & primed the ceiling but the bad installation of drywall is showing through and the tape is very visible and I'm not happy with the results. Any suggestions? Also there's visible tape throughout the walls of the house. Before we paint should we re-mud and sand before painting or do we have to remove the tape to get a smooth look to the wall? Help.