Now you can use the same epoxy resin with a choice of three different hardeners - slow, medium, and fast set. This slow set epoxy mixes at a 2:1 ratio. It is great for flexible repairs on delams and when hight strength is a concern. It is a slow set epoxy so it takes aprox. 4 hours to set, but you have 30 minutes of working time. Developed for custom wood boat construction, System Three has the best strength along with great flexibility. You will not find a better epoxy for doing all phases of repair. Kit includes 2 pumps.