I've recently moved into a house where the previous owner has painted all of the coving with vinyl silk emulsion. They have used a brush rather than a roller which has left some very pronounced brush marks. I've sanding the coving down and applied matt emulsion with a gloss roller but as it dries bits of the previous paint raise up to give a pretty awful look? If I sand down and paint 4 or 5 times I finally get an acceptable finish but the time that it is taking is ridiculous. Does anyone have any suggestions on how to solve this problem more effectively. I've thought about maybe painting a few coats of gloss undercoat to act a a sealer and a filler/primer.