PPG PR1425B-2 (100-ML-SEMKIT)

PR-1425 Class B Windshield and Canopy Sealant

Overview

PR-1425 Class B is a two-component, dichromate-cured polysulfide sealant developed by PPG Aerospace for aircraft windshields, canopies and other transparent aircraft sealing applications. Formulated as a low-sag, thixotropic paste, it provides excellent adhesion to properly prepared glass, acrylic and polycarbonate substrates without causing crazing. Designed to perform across a wide temperature range, the cured sealant offers outstanding resistance to UV exposure, weathering, aviation fluids and pressure cycling, making it ideal for both OEM production and MRO operations.

Key Technical Specs

• Product Type: Two-component polysulfide windshield and canopy sealant
• Class: Class B
• Colour: Black
• Mix Ratio (by Weight): 100 Parts B : 12 Parts A
• Application Method: Extrusion gun or spatula
• Service Temperature Range: -54°C to +121°C (-65°F to +250°F)
• Intermittent Temperature Exposure: Up to +135°C (+275°F)
• Specific Gravity (Cured): 1.49
• Non-Volatile Content: 93%
• Ultimate Hardness: 55 Shore A
• Application Life: 30 minutes (B-1/2), 1 hour (B-1), 2 hours (B-2)
• Storage Life: Minimum 9 months

Approvals & Specifications

• AMS-G-25667 (Glass)
• MIL-PRF-8184 (Acrylic)
• AMS-P-83310 (Polycarbonate)
• AMS5516 (Stainless Steel)
• AMS4911 (Titanium)
• AMS4045 (Aluminium)
• Compatible with PR-142 Adhesion Promoter

Typical Applications

• Aircraft windshield sealing
• Aircraft canopy sealing
• Glass, acrylic and polycarbonate glazing installation
• Aircraft transparency replacement
• OEM aircraft manufacturing
• Aircraft maintenance, repair and overhaul (MRO)
• General aerospace weatherproof sealing

Key Features & Benefits

• Excellent adhesion to common aircraft transparency materials.
• Specially formulated to avoid crazing of acrylic and polycarbonate.
• Outstanding resistance to UV radiation and weather exposure.
• Excellent flexibility over a wide operating temperature range.
• Maintains pressure integrity under thermal cycling.
• Resistant to aviation fuels, hydraulic fluids, lubricants, water and alcohols.
• Excellent repairability to both fresh and fuel-aged sealant.
• Available in Semkit®, Semco® cartridges and preformed parts using PPG ARE™ technology.

Application Guidelines

• Clean all primed surfaces immediately before sealant application using approved aerospace solvents.
• Use lint-free cloths and avoid contaminating clean solvent supplies.
• Dry the surface with a second clean cloth to prevent contaminant redeposition.
• Evaluate adhesion on production substrates before full-scale application.
• Follow SAE AIR 4069 recommendations for optimum surface preparation.
• Apply using an extrusion gun or spatula according to the selected Class B application life.

Compatibility & Limitations

• Compatible with properly prepared glass, acrylic and polycarbonate substrates.
• Suitable for aluminium, titanium and stainless steel when correctly prepared.
• Requires appropriate surface preparation for optimum adhesion.
• Designed specifically for aircraft transparency sealing applications.
• Not intended for structural bonding applications.

Packaging & Procurement

• Supplied in two-part can kits
• Available in Semkit® injection kits
• Available in pre-mixed frozen Semco® cartridges
• Available as preformed parts using PPG ARE™ technology
• Minimum shelf life: 9 months (two-part kits and Semkits®)
• Frozen Semco® cartridges: Minimum 28-day storage below -40°C

Why This Product is Chosen for AOG / MRO

• Excellent sealing performance for aircraft transparencies.
• Prevents crazing of acrylic and polycarbonate windows.
• Outstanding weather and UV resistance for long service life.
• Available in multiple packaging formats to suit field and workshop repairs.
• Maintains flexibility and sealing integrity in demanding operating environments.

Practical Suggestions for Your Team (AOG Mindset)

• Always clean substrates immediately before applying the sealant.
• Use fresh lint-free cloths throughout the cleaning process.
• Select the appropriate Class B application life based on repair size.
• Keep frozen cartridges at the recommended storage temperature until required.
• Confirm compatibility with the aircraft maintenance manual before application.

Manufacturer / Aviation Spec Codes

• Product Name: PR-1425 Class B Windshield and Canopy Sealant
• Manufacturer: PPG Aerospace (PRC-DeSoto)
• Product Type: Two-component dichromate-cured polysulfide sealant
• Compatible Primer: PR-142 Adhesion Promoter
• Primary Specifications: AMS-G-25667, MIL-PRF-8184, AMS-P-83310