Bath wall was previously painted with old paint and is rough. I heard ages ago you could shellac it and when dry paint over it and it would make it smooth. Looking for solution soon to paint, any ideas will be appreciated Thanks.
Any primer will help not just a shellac primer. It is best to do a little sanding to reduce the roughness then apply a primer. Use 150 grit sandpaper and a little elbow grease. Use a sanding pole if the walls are large. Sanding poles are cheap and can be found at any hardware store. This will help reduce the roughness.