Extreme Block Interior/Exterior Stain Blocking Waterbased Primer

Description

Permanently isolate stubborn architectural stains across any environment with Sherwin-Williams Extreme Block Interior/Exterior Stain Blocking Waterbased Primer. This high-performance, rapid-drying acrylic sealer is engineered to deliver heavy-duty stain-suppression performance that rivals traditional oil-based primers, all while maintaining a low-odor, easy-cleanup waterbased profile. Formulated with advanced blocking resins, it creates an impenetrable barrier that locks down bleeding stains from water rings, smoke soot, char, grease markers, crayons, ink, and wood tannins. It flows smoothly over multiple substrates—including interior drywall, plaster, exterior wood siding, trim, and cured masonry—sealing porous surfaces to ensure a completely uniform topcoat sheen holdout. Its fast-drying characteristics let you apply premium latex or oil topcoats in as little as two hours, drastically shortening your renovation timelines.