Elastopatch Flexible Patching Compound is a high performance, smooth elastomeric spackling compound that eliminates reoccurring cracks by providing a permanently flexible fill. This ready-to-use patching compound is excellent for use on a variety of interior and exterior surfaces, including drywall/plaster, wood, stucco, brick, and other masonry surfaces requiring a permanently flexible seal. It has superior paintability so it won't flash paint. However, it is NOT SANDABLE.