PPG PR1826B-1/4- A1001 (100-ml-Semkit)

PR-1826 Class B Rapid Curing Fuel Tank Sealant

Overview

PR-1826 Class B is a two-component, epoxy-cured polythioether fuel tank sealant developed by PPG Aerospace (PRC-DeSoto) for aircraft integral fuel tanks and fuselage sealing applications. Formulated as a low-sag, thixotropic paste, it is designed for fillet sealing and can be applied by extrusion gun or spatula. Unlike conventional polysulfide sealants, PR-1826 cures at low temperatures and is unaffected by changes in relative humidity. Once cured, it provides outstanding resistance to aviation fuels, hydraulic fluids, lubricants and harsh aerospace operating environments.

Key Technical Specs

• Product Type: Two-component epoxy-cured polythioether fuel tank sealant
• Class: Class B
• Colour (Mixed): Dark Grey
• Mix Ratio (by Weight): 100 parts Part B : 8.5 parts Part A
• Application Method: Extrusion gun or spatula
• Service Temperature: -62°C to +160°C (-80°F to +320°F)
• Intermittent Temperature Excursions: Up to 216°C (420°F)
• Specific Gravity (Cured): 1.47
• Non-Volatile Content: 96%
• Ultimate Hardness: 47 Shore A
• Application Life: 15 minutes (B-1/4), 30 minutes (B-1/2), 2 hours (B-2)
• Storage Life: Minimum 9 months

Approvals & Specifications

• AMS 3277 Type I Class B
• Compatible with PR-1826AP Adhesion Promoter
• Surface preparation guidance references SAE AIR 4069
• Cleaning cloths should conform to AMS 3819

Typical Applications

• Aircraft integral fuel tank fillet sealing
• Aircraft fuselage sealing
• Fuel tank manufacturing
• Fuel tank repair and overhaul
• General aerospace sealing where fuel resistance is required
• OEM aircraft production and MRO maintenance

Key Features & Benefits

• Rapid curing reduces aircraft production and maintenance time.
• Excellent resistance to jet fuel and aviation gasoline.
• Cures reliably even at lower temperatures and is unaffected by humidity.
• Low-sag thixotropic consistency allows easy fillet application.
• Outstanding adhesion when used with PR-1826AP Adhesion Promoter.
• Excellent flexibility at extremely low temperatures.
• Highly resistant to hydraulic fluids, lubricating oils, alcohols and water.
• Excellent repairability to both freshly cured and fuel-aged sealant.
• Excellent sanding and shaving characteristics after cure.

Application Guidelines

• Clean substrates thoroughly using approved aerospace solvent cleaning procedures.
• Use fresh lint-free cloths conforming to AMS 3819.
• Apply PR-1826AP Adhesion Promoter in a thin, uniform coat and allow approximately 30 minutes to dry.
• Do not apply adhesion promoter below 7°C (45°F).
• Apply the sealant within 8 hours after applying the adhesion promoter.
• Mix according to the supplied Semkit® instructions before application.
• Apply using an extrusion gun or spatula depending on the sealing configuration.

Compatibility & Limitations

• Designed for aircraft fuel tanks and aerospace sealing applications.
• Compatible with common aircraft metallic substrates when properly primed.
• Requires PR-1826AP Adhesion Promoter for optimum adhesion.
• Adhesion promoter should not be used if particles or precipitate are present.
• Surface preparation should follow SAE AIR 4069 recommendations.

Packaging & Procurement

• Supplied in Semkit® packaging
• Available in multiple application life variants (B-1/4, B-1/2 and B-2)
• Minimum shelf life of 9 months
• Store between 15°C and 27°C in original unopened containers

Why This Product is Chosen for AOG / MRO

• Rapid curing minimises aircraft downtime during fuel tank repairs.
• Excellent resistance to aviation fuels ensures long-term sealing performance.
• Maintains flexibility under extreme temperature conditions.
• Provides durable repairs compatible with demanding aerospace environments.
• Easy repairability simplifies future maintenance activities.

Practical Suggestions for Your Team (AOG Mindset)

• Choose the appropriate application life (B-1/4, B-1/2 or B-2) based on repair size.
• Ensure adhesion promoter is applied only to freshly cleaned surfaces.
• Do not exceed the recommended 8-hour sealing window after priming.
• Store Semkits within the recommended temperature range to maximise shelf life.
• Always inspect mixed sealant for uniform colour before application.

Manufacturer / Aviation Spec Codes

• Product Name: PR-1826 Class B Rapid Curing Fuel Tank Sealant
• Manufacturer: PPG Aerospace (PRC-DeSoto)
• Product Type: Two-component epoxy-cured polythioether fuel tank sealant
• Specification: AMS 3277 Type I Class B
• Recommended Primer: PR-1826AP Adhesion Promoter