For repairing missing or loose grout and hairline cracks. A fast hardening, permanent and natural-looking, textured grout repair is now available. Repairs can be made on any grout problem, including low or dented grout lines. Rock Hard Grout speed repair sets up fast, so mix in small batches of not more than three tablespoons. These repairs will thoroughly bond to the original grout without failure. Repairing grout with regular grout will fail due to poor bonding and curing properties. Following your repairs, color sealer can be applied within 20 minutes. Complete your repairs by concealing any evidence of the repair by applying color sealer.