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Naftoseal MC-780 Class B-1/2 Fuel Tank & Fuselage Sealant

Silmid P/N: VAR0001003
From £60.63 (excl VAT) £72.76 (Inc VAT)

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. The B-1/2 denotes that this product has a 1/2 hour application time.

Product Properties

Chemetall Naftoseal®
Sealant Class
Class B
Application Time
30 Minutes


AIMS 04-05-001 | AIMS 04-05-012 | AIMS 04-05-014 | AIMS 04-05-015
Miscellaneous Specs
BAMS 552-008 | BAMS 552-009 | MEP 09-084

Please Note: Specifications and approvals are subject to change at any time. Users should always consult their AMM or the OEM when selecting products to ensure items have the release needed. Only specifications listed on the order confirmation will be certified on the Silmid CofC.

Product Information

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 -55C (-67F) to +130°C (+ 266F) and withstand a short term temperature of +182C (+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. 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 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).


Sealing fuselages and fuel tanks

Specifications Approvals:

  • AIMS 04-05-001 -012, -014 -015,
  • NTA 65361, MDL 6058,
  • BAMS 552-008 -009,
  • CMS-SL 101 104,
  • MEP 09-084, 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 onesmall 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.

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.