Rustins One Coat Damp Seal Paint 250ml Seals and Blocks Damp and Water Stains. Rustins One Coat Damp Seal 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. Type: A quick drying interior high performance solvent based paint based on polyester. Intended Use: For covering damp walls and ceilings, water stains and most household stains. Special Features: Quick drying and can be over coated with gloss or emulsion paint as well as wall paper. Not for exterior use. It dries with a long lasting permanent seal over damp.