DAPÂ® DYNAFLEX 230Â® delivers a silicone tough latex formulation for outstanding exterior performance against the elements. Developed for flexibility and crackproof performance, this sealant endures expansion and contraction without cracking or losing its seal. The paintable, durable sealant can fill gaps up to 1 in wide and the cured sealant is mold-and mildew-resistant. It has excellent adhesion to a wide range of building materials including wood, MDF, PVC, polystyrene and composite trimboard. Easy to gun out, tools smoothly and can be cleaned up with soap and water. Interior/exterior use. Meets ASTM Specification C920, Class 25.