Rustins one coat damp seal rustins dams500 this 500ml tin of damp seal from rustins is a fast drying high performance interior paint which permanently covers damp water stains and most household stains it dries with a long lasting permanent seal over damp walls and ceilings and can be over coated with gloss or emulsion paint as well as wallpaper it does not cure the damp but is specially formulated to allow trapped moisture to escape over time so preventing flaking of the paint or peel