I hired Jim from J.K. Schwartz to fix my stamped concrete patio. It had so many layers of sealer on it that it began to flake off in many areas. It had white marks all over it as well and it was just plain ugly. Jim suggested having the old sealer stripped off to the bare surface and sealed all over again with an acrylic sealer. I went ahead and had it done and after the job was complete, my patio looked like it was brand new again. He added more color when he was done and it looked great. No more flaking and no more white marks. I was stunned at how it turned out. I highly recommend this company; they are honest and very knowledgeable and honest.