Hercules Multi-Purpose Silicone Sealant is a high quality joint sealant that cures to form a low modulus, water resistant bond. An interior/exterior sealant that remains flexible and has excellent adhesion to a wide range of materials. This product skins in 10 minutes with a curing rate of ¼” /48 hrs. MPA-20 meets ASTM C920, Type S, Grade NS, Class 25, Use NT, A, G and O, as well as Federal Specification TT-S-00230C, Type II, Class A.
