NAFTOSEAL® MC-780 Class B is a two-component, manganese-dioxide cured polysulfide polymer
system with low density providing excellent fuel tank and fuselage seals. It has outstanding resistance
to aviation gasoline and jet fuel, as well as resistance to the chemicals and petroleum products used in
the aircraft industry. Additionally it was developed for a service temperature between -55 °C (-67 °F) to
+130 °C (+ 266 °F) and withstand a short-term temperature of +182 °C (+360 °F).
NAFTOSEAL® MC-780 Class B maintains its flexibility and bond strength on most metal substrates like
aluminium, stainless steel, steel, titanium, composite and many coatings under extremes of
temperature, weathering and stress.
The mixed compound is a thixotropic paste easily applied by extrusion, injection gun or spatula. It has
excellent tooling properties.
NAFTOSEAL® MC-780 Class B can be mixed by MCI-Mixer (Techkits as well as Semkits) or by
appropriate 2-component mixing and dosing systems. The curing time may be reduced considerably by
increasing the temperature (up to 60 °C or 140 °F max)
