Rust-Oleum® Fast-Patch is a two-component epoxy putty that is designed to fill minor cracks, spalls, and low spots as well as vertical cracks and slab damage. It does not have to reach full cure to be profiled prior to coating. This makes it ideal for new installers filling hairline cracks, pits and small surface flaws. Fast Patch is the quickest, easiest way to make repairs without the use of any extra equipment. 2-Part epoxy - 1:1 mix ratio. Paintable immediately. Fills cracks up to 1/4" deep. Heavy-duty formula permanently bonds concrete. Will not shrink or crack. Use for patching cracks and holes in concrete and masonry.