MAS Medium Hardener is a polyamine blend intended for moderate reactivity and resistance to amine blushing. Moderate pot life, gel, and thin film set times provide advantages when filleting and fairing. MAS Epoxy and Medium Hardener, when mixed with thickeners, gel and set quickly enough to avoid draining and sagging, while still allowing ample flow time for controlled application periods. Medium Hardener is recommended when overnight sandibility is more important than continuous laminating and open time (as provided by MAS Slow Hardener). Will also provide a beautifully smooth void free finish, with great resistance to milking out during application and fogging in critical clear coating applications.