Our newest hardener options. Both are DOT non-corrosive and ship without any hazmat concerns. Although the NC hardeners give slightly high mixed viscosities, their non-corrosive nature gives an extra margin of safety and minimizes the potential skin irritation of other hardeners. Fast NC features a pot life of 15-20 minutes and thin film set of 1.5-2.0 hours while Medium NC has a pot life of 25-30 minutes and a thin film set of 2.5-3.0 hours.