Pettit EZ Prime High Build Topside Undercoater Pettit EZ Prime is a high-build formula that dries quickly and is easy to sand. This undercoater should be used as a base coat whenever the surface beign painted is aged, cracked, checked, pitted, or in any way less than smooth. It can be applied to fiberglass, wood, and previously painted surfaces. EZ Prime has excellent filling properties which can be used for a full, one-coat application. When using on bare wood, seal with Pettit EZ Wood Sealer t