Gorilla glue is a polyurethane glue when exposed to moisture the adhesive reacts and creates a foaming action that fills whilst it sticks gorilla glue has an open working time of 20 minutes the glue is brown in colour but dries a tan colour and is totally waterproof gorilla glue is incredibly strong bonding all types of wood including pressure treated wood it also bonds stone metal ceramics foam glass leather and more once dried the product is sandable stainable paintable and can also take a var