€¢ Interior & exterior use €¢ Best exterior wood sealer €¢ Blocks cedar & redwood bleed €¢ Seals water; smoke & nicotine stains €¢ Sticks to all surfaces without sanding €¢ Dries in 1 hour Get ultimate hiding power indoors and out with Zinsser® Cover Stain® oil-base primer. This whole-house primer-sealer is a favorite with professionals. Use it to block stains; hide dark colors; prevent tannin bleed and penetrate and seal exterior wood. Can be used under any oil- or water-based topcoat."