Flamemaster CS5500N Class B AMS-3276 - High Temperature Fuel Tank Sealant 

CS 5500N Class B is a two-part, chemically curing polysulfide fuel tank sealant specifically formulated for higher temperature service in aircraft. It is designed to maintain its excellent sealing properties, flexibility, and fuel resistance even when exposed to elevated operational temperatures, which are common in modern high-performance aircraft or specific areas of the fuel system. The "Class B" designation indicates a trowelable consistency, allowing for convenient application by spatula or extrusion gun for filleting, sealing seams, fasteners, and small access panels. Upon curing, it forms a tough, resilient rubber that provides a durable, leak-proof barrier against a wide range of aviation fuels, lubricants, and hydraulic fluids across a broad temperature spectrum.

Key Features for Aviation:

• Two-Part System: Comprises a base compound and an accelerator, mixed immediately prior to application.
  
• Polysulfide Chemistry: Provides the fundamental excellent resistance to aviation fuels and other aircraft fluids.
  
• Higher Temperature Resistance: Engineered to perform reliably at elevated continuous operating temperatures (e.g., up to 250°F / 121°C, and intermittently higher), distinguishing it from standard fuel tank sealants.
  
• Class B Consistency: Trowelable, suitable for application with a spatula, spreader, or extrusion gun for forming fillets and sealing larger areas.
  
• Excellent Adhesion: Forms strong, long-lasting bonds to typical aircraft substrates like aluminum, titanium, stainless steel, and composite materials.
  
• Superior Fuel and Fluid Resistance: Highly resistant to aviation jet fuels (JP-4, JP-5, JP-8, Jet A/B), hydraulic fluids (e.g., Skydrol), and engine oils.
  
• Flexibility and Resilience: Cures to a flexible, rubbery seal that can withstand aircraft vibrations, thermal cycling, and structural movement without cracking or delaminating.
  
• Good Work Life (Pot Life): Provides sufficient time for application before curing begins, depending on the specific "B" class variant (e.g., B-1/2, B-2, B-4 indicating pot life in hours).
  
• Cures at Room Temperature: Cures efficiently at ambient temperatures, though elevated temperatures can accelerate the cure.

Typical Aviation Applications:

• Sealing Integral Fuel Tanks: Crucial for preventing fuel leaks in the main fuel containment structures within wings and fuselage.
  
• High-Temperature Fuel Tank Sections: Specifically applied in areas of the fuel tank near heat sources (e.g., engines, hot air ducts) or in high-performance aircraft where fuel temperatures can elevate.
  
• Fastener and Seam Sealing: Used to seal around rivets, bolts, and along structural seams within fuel tanks to ensure a hermetic seal.
  
• Access Panel Sealing: Applied to seal removable access panels on fuel tanks or other compartments exposed to high temperatures and aviation fluids.
  
• Filleting and Void Filling: Employed to create smooth fillets around joints and fill small voids within fuel-wetted areas to improve flow and prevent fluid entrapment.
  
• Repair of Fuel Tank Leaks: Used for both production and repair, offering a durable solution for leaks in demanding temperature environments.

• All in-stock orders are processed within 1–2 business days (excluding weekends and holidays) after receiving your order confirmation email.
• Orders with a lead time will ship according to the estimated shipping time shown on the product page.
• If we experience a high volume of orders or if an item is backordered, processing times may be slightly delayed. We will notify you promptly via email.

• Returns must be made within a maximum of 3 business days after receiving the product, with prior authorization from Aircraft Shop Supply (Return Material Authorization). Returns without prior notice or written authorization will not be accepted.
• For products with 3 to 6 months of remaining shelf life, claims must be made within the next 2 business days after receipt.
• Returns are not accepted for products with less than 3 months of remaining shelf life.
• Returns are not accepted for products purchased during a low Shelf Life promotion, items sold with discounts, or special orders that must be placed directly with the factory.
• The customer is responsible for the return shipping cost, except in cases where the return is due to an error on the part of Aircraft Shop Supply.
• Refunds will only be issued after the product has been inspected and no damage is found.
• A 25% Restocking Fee will be charged for returns of products in good condition that are either no longer needed or were ordered incorrectly.
• A 35% Restocking Fee will be charged for returns of products with one year or less of remaining shelf life.
• No Restocking Fee will be charged if Aircraft Shop Supply is responsible for incorrectly shipping a product, or if the order is damaged upon leaving the warehouse.
• Hazardous Materials & Dangerous Goods: These items are sold as final and are not eligible for return approval.