Castlebond is a clear epoxy resin, which is specially formulated for use as an aggregate- bonding compound for paths, drives and vehicle hard-standings. Castlebond is mixed with washed aggregates, spread and tamped into position where it cures to form a tough yet flexible surface. Because each grain is coated with resin, the surface is easy to keep clean, weeds and algae cannot get a grip and oil stains are simply washed away.