SikaBiresin CR72-3 is the Slow Hardener for the CR72 Epoxy Laminating System. When combined with the CR72 Resin, (sold separately), it is a 100% solid system developed for the fabrication and repair of high performance composite stuctures. It produces a low viscosity mixture and a convenient volumetric mix ratio, It is specifically formulated for standard wet lay-up or resin-infusion operations requiring the highest degree of fabric wetting and air release attributes.