There was no sludge really - That would have alerted me. Its just that I didn't wash the wall to remove any thin residue. i'd hate to have to start again but don't want to regret it. Guardz over the painted surface?????
In my haste to get the job done I forgot to wash off the wallpaper paste left after removal of a vinyl border below the coving. I have only given the wall one thinnned coat of white Dulux Matt. Can I go over this with Zinnser Gardz and continue painting, or should I rub off the paint, apply...