Description All Purpose Crack filler is a tough filler formulated with a unique blend of cement and plaster to provide a weather resistant and flexible surface for both interior and exterior applications. RECOMMENDED USES: All Purpose Crack filler seals and fills cracks & holes in materials such as plaster, brick, and concrete, stone & asbestos fibre board. Fills gaps around door & window frames to replace loose mortar. Fills and repairs damaged mortar.