This sometimes happens on very porous stone and can be over come by varying the application method. The surface needs a pre-seal to hold the STAIN-PROOF^® Premium Impregnating Sealer, formerly known as STAIN-PROOF Original™, closer to the surface. Apply the first coat, and after 10 minutes wipe off the excess. Allow the product to cure for a minimum of one hour (24 hours is even better!). Then apply a second coat of Premium Impregnating Sealer and polish off the excess after it becomes touch dry or a minimum of 10 minutes. Please note that most STAIN-PROOF sealers are reactive and therefore take over two to three weeks to fully cure.