The surface you want to seal has to be thoroughly cleaned. If you are using Grout, Tile & Stone Sealer – Slow Drying, apply the first coat. When dry, apply the second coat and buff before it dries. The first coat may take up to five hours to dry. If using Grout, Tile & Stone Sealer – Quick Drying, apply one coat. Wait up to sixty minutes and apply the second coat. Buff the area before it dries. A lambswool applicator or buffing pad is best to use depending upon the size of the area.