Product Description: 400W White is an ultrapremium solvent based primer/sealer/bonder developed to meet Federal and State VOC requirements and solve many paint bonding problems It provides excellent adhesion, sealing and bonding on many hard-to-coat surfaces. Clean and dull paintable surfaces may not need sanding, but sanding or dulling the surface is required on hard, glossy surfaces for maximum adhesion. This product can be used for both indoor or out-door applications and can be used with either oil/alkyd or latex topcoats. Not recommended under strong solvent topcoats such as lacquers or two component epoxies or urethanes. 400W is recognized as the leading bonding primers for though-to-coat surfaces by major painting contractors.