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Naftoseal MC-780 Class C-2 Fuel Tank & Fuselage Sealant

Silmid P/N: VAR0000992
From £46.29 (excl VAT) £55.55 (Inc VAT)
NAFTOSEAL® MC-780 Class C is a two-component, manganese-dioxide cured polysulfide polymer system with reduced density providing excellent fuel tank and fuselage seals. 

Technical Information

  • Commodity Code 32141010
  • Country of Origin Germany

Product Information

Naftoseal MC-780 Class C is a two-component, manganese-dioxide cured polysulfide polymer system with reduced density providing excellent fuel tank and fuselage seals. It is designed for interfay surface sealing and wet riveting of fuselage components and 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 C 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 C combines low viscosity, for ease of mixing, with a high thixotropy giving good application characteristics. It can be effectively applied by extrusion, by injection gun, or by using a roller coating technique. The low viscosity means that it is easily squeezed from interfacing surfaces during the assembly process. It has a unique „self-filleting“ characteristic.

Naftoseal MC-780 Class C can be mixed by MCI-Mixer 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).

Applications: Sealing fuselages and fuel tanks

Specifications & Approvals:

  • AIMS 04-05-001 & -012, -014 & -015, 
  • NTA 65361, MDL 6058, 
  • CMS-SL 101 & 104, ECS 0045

Please Note: the above list of specifications is subject to change and may not apply to all sizes and all grades. Please refer to the product title for a full breakdown of the specifications this product will be released to.

Surface Preparation:

To obtain good adhesion, clean surfaces with appropriate cleaners (e.g. Chemetall's  Ardrox products like Ardrox 5529 or Ardrox 5575) to remove dirt, grease and processing  oils just prior to sealant application. Use lint-free rags or paper towels that are free of oil. 

Always pour cleaner on the cloth to avoid contamination of the cleaner supply. Clean one  small area at a time, quickly wiping it dry before the cleaner's solvent evaporates to prevent  redeposition of oil, wax or other contaminants. Usually, in the case of most epoxy resin  primers, surfaces need not be additionally prepared with an adhesion promoter to improve  adhesion. PUR and EP topcoats as well as composite components should be pre-treated  by the Naftseal MC-115 Adhesion Promoter.


  • Naftoseal MC-780
  • Class C-2 Fuel Tank & Fuselage Sealant
Click here to view further Naftoseal literature in our brochures section. 

Shipping information

Orders over £100 placed online will now qualify for FREE UK Mainland delivery*

Orders under £100 placed online for UK Mainland delivery is £12.00*

**Orders requiring Pre 10.00am Next Day delivery has also been lowered from £35.00 to £30.00, orders placed through the office will incur additional charges.** 

International delivery (door to door delivery) is available for selected countries worldwide. Shipping will be automatically calculated based on the weight, location and hazardous nature of the goods. Customers can also choose ex works to arrange their own collection.

Please refer to our delivery page for more information.