Dymonic FC High-Performance, Fast-Curing, Single-Component, Hybrid Sealant Dymonic FC is a high-performance, fast-curing, single-component, low-modulus, hybrid sealant, formulated with proprietary silane end-capped polymer technology. Basic Uses Dymonic FC is a durable, flexible, sealant that offers excellent performance in moving joints and exhibits tenacious adhesion once fully cured. Typical applications for Dymonic FC include expansion and control joints, precast concrete panel joints, perimeter caulking (windows, door, panels), EIFS, aluminum, masonry and vinyl siding.