STEINA Exterior Primer Sealer STEINA Stain Blocking Primer for decks, fences and siding is a quick-drying product. This linseed alkyd oil primer helps eliminate the natural staining and discoloration sometimes seen on wood subject to extractive bleeding such as red cedar, redwood, fir or pine. It is formulated for maximum breathability and provides a superior base coat for all latex and oil finishes. Recommended use : Clapboards, siding, shingles, trim, shakes and hardboard.