J-B Weld Plastic Bonder Black Syringe is a quick-setting, two-part, urethane adhesive system that provides strong and lasting repairs and works on thermoset, carbon fiber composites, thermoplastics, coated metals, concrete & more. Plastic Bonder has a 1:1 mixing ratio, sets in 15 minutes and can be sanded after 30 minutes. With a tensile strength of 3770 PSI, Plastic Bonder sets to a black color and cures to a hard, permanent bond.