Hello Have just stripped old wallpaper off, I discovered it had also removed jagged areas of a weird rubbery paint underneath that had been applied to bare plaster without an initial mist coat. Tiny areas of the paint continue to form nibs all over the place. See photos attached. I cannot get a decent smooth surface for wallpapering. I was hoping I could just slap a coat of PVA (1:4??) over the whole lot ie the bare plaster and the weird paint to seal off the problem, before lining the walls and painting with emulsion paint Would this work? If so, would I still need to size it? Or are there any better solutions?