Leach Stop 5G $376.55 Leach Stop – 5 Gallon Pail Leach Stop is an invisible, protective barrier that helps to prevent architectural precast, GFRC, concrete, and natural stone surfaces from leaching minerals onto adjacent glass and metal surfaces which causes stains. It protects the stone surfaces from water penetration and is designed for high-performance building restoration and preservation applications. Leach Stop Carries a 10-Year Warranty. Add to cart