General Finishes Professional Enduro White Undercoat is similar to General Finishes Sanding Sealer with the addition of white colorant to provide a primer undercoat for white/off-white wood finishes. Want to tint to a darker color? Use Enduro Deep Base Primer instead. Both are EXTERIOR rated and tintable, and the high solids, heavy-bodied formula facilitates a fast film build and easy sanding. Use as a basecoat for pigmented finishes. It dries tack-free in 30+ minutes. Particularly effective on MDF. Learn more about General Finishes' entire finishing system of clear and pigmented primers, acrylic and polyurethane clears, pigmented topcoats, and water-based stains.