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 varnish. Due to its foaming action the glue gives greater coverage - up to 3 times the coverage of other glues. 
This glue is unaffected by extreme hot and cold and will not break down when exposed to rain and snow.

The Gorilla Glue formula bonds materials that typical all-purpose adhesives will not hold, including wood, stone, metal ceramics, glass, foam and even bonds dissimilar materials. 
It is waterproof and temperature resistant, which means it can be used for indoor and outdoor projects and repairs.

Originally used as a commercial adhesive for hard-to-glue materials. 
Once something is glued it will not come undone - it is set to survive years after the repair.