BONDERITE C-AK VITRO-KLENE AERO BONDERITE C-AK VTKL AERO / TURCO VITRO-KLENE Hot tank caustic cleaner for ferrous and titanium alloys. BONDERITE® C-AK VTKL AERO ALKALINE CLEANER is a brown granular mixture formulated to remove drawing compounds, lube oil, rust preventive compounds, and other tenacious soils from ferrous and titanium alloys prior to vitreous enameling and other processes that require a high degree of cleanliness.