Every airplane is held together by hundreds of thousands - sometimes millions of rivets and threaded fasteners. Today most are wet-installed; i.e., coated with sealant to reduce galvanic corrosion and to seal moisture out (or fuel in). The wet installation process is time-consuming and environmentally problematic, and installation quality can be operator-dependent.
Machine application of pre-mixed but cure-blocked AMS3277 polythioether sealant directly to the fastener. The cure-blocked sealant is then covered by a nanocomposite high Tg "skin" that is impermeable to moisture. When the fastener is driven, installation stresses fracture the skin and ambient water vapor de-blocks the reaction and kicks off the normal sealant cure process.
In development (Navy Phase II SBIR).