Zinsser Ready Patch Spackling & Patching Compound is designed to combine the workability of spackling paste with the strength of plaster to provide long-lasting results. It is smooth, easy to apply and sand, and very hard when cured. Ready Patch is recommended for application to new or previously painted wood (including plywood, T-1-11, and pressure-treated wood), hardboard, metal (including aluminum, iron, steel, copper, and galvanized metal), drywall, cured plaster, masonry (including stucco, concrete block, poured concrete, and brick). Ready Patch will adhere to glossy surfaces such as metal and tile, provided such surfaces are clean and free of contamination or free of poorly adhered existing finishes.