Naftoseal® MC-780 A-1/2 Fuselage & Fuel Tank Sealant – TechKit 130

1 Description
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 shortterm temperature of +182 °C (+360 °F).
Naftoseal® MC-780 Class B maintains its flexibility and bond strength on most metal
substrates like aluminum, stainless steel, steel, titanium, composite and many coatings under
extremes of temperature, weathering and stress.
Naftoseal® MC-780 Class B can be mixed by MCI-Mixer or by appropriate 2-component
mixing and dosing systems.
The mixed compound is a thixotropic paste easily applied by extrusion, injection gun or
spatula. It has excellent tooling properties. For a good surface finish Naftosmooth can be
used after application.
The curing time may be reduced considerably by increasing the temperature (up to 60 °C or
140 °F max).