Zinsser Odorless Oil-Based Stain Blocker. Gallon. For when you need the stain-blocking performance of an oil-based primer without any solvent odor. This low-VOC primer is specifically designed to seal tough stains in indoor areas where people are present. Seals stains from water, fire and smoke damage. Oil-base performance when odor is a concern. Non-yellowing, dries flat, sands easily. Use with all topcoats. VOC compliant sprayable formula. For best results, allow to dry two hours before next coat. Kills stains from water, graffiti, ink and crayon, for masonry, plaster and fast-set joint compounds and more features.