Professional Patching Compound for Interior and Exterior Repairs Zinsser® MH Ready Patch™ Professional Spackling & Patching Compound combines the workability of spackling paste with the strength of plaster for durable surface repairs. The smooth compound is easy to apply and sand and cures to a hard, long-lasting finish. Multi-Surface Adhesion Ready Patch can be applied to new or previously painted wood, plywood, T-1-11, pressure-treated wood, hardboard, drywall, cured plaster, masonry, and metal. Compatible metals include aluminum, iron, steel, copper, and galvanized metal. It also adheres to clean glossy surfaces such as metal and tile when they are free of contamination and poorly adhered existing finishes. Hard, Smooth Finish for Patching and Repair The compound cures to a very hard, smooth surface. Because fully cured Ready Patch can become more difficult to sand after drying overnight, sanding should be completed as appropriate during the repair process. After patching, spot-prime repaired areas and apply an appropriate primer to the entire surface for best results. Off-White Finish with Tinting Capability Ready Patch is supplied in an off-white color. When greater contrast with the substrate is needed during application, a few drops of universal colorant can be thoroughly blended into the compound.