Primer E is a two-component, 100%-solids epoxy primer and bonding agent designed for use with MAPEI self-leveling underlayments using MAPEI’s sand broadcast method. Primer E is the most effective method for bonding to nonporous, dense substrates before installing self-leveling underlayments subject to high stress. Primer E’s low viscosity makes installation fast and easy, and provides excellent penetration into the substrate and therefore a tenacious bond.