3M Aerospace Sealant AC-665 Class B are two-part, manganese-cured, chromate containing, corrosion inhabiting sealants. These Sealants provide an effective barrier against the common causes of corrosion on aluminum and between dissimilar metals. 3M AC-665 Class B Sealants have outstanding resistance to aviation gasoline and jet fuel, as well as resistance to chemicals, hydraulic fluids and petroleum products common to the aircraft industry. The mixed compound is a thixotropic paste, easily applied by spatula, extrusion gun or injection gun. They maintain flexibility and bond strength on most metal substrates under extremes of temperature, weathering stress.Information provided by 3M |