PPG PR187 (1-USPT-CAN)

PR-187 Adhesion Promoter

Overview

PR-187 Adhesion Promoter is a one-component adhesion promoter developed by PPG Aerospace (PRC-DeSoto) to improve the bonding performance of polythioether sealants on a wide variety of aerospace substrates. It is particularly recommended when PR-1800 series polythioether sealants are applied over existing polysulfide sealants. PR-187 dries rapidly at room temperature, does not soften existing finishes, and enhances long-term sealant adhesion in demanding aerospace environments.

Key Technical Specs

• Product Type: One-component adhesion promoter
• Appearance: Clear green solution
• Application Method: Brush or clean gauze
• Dry Time: Approximately 30 minutes at 25°C (77°F), 50% RH
• Specific Gravity: 1.10
• Effects on Finishes: Does not soften existing finishes
• Storage Life: Minimum 9 months below 27°C (80°F)
• Moisture Sensitivity: Hygroscopic; protect from moisture

Approvals & Specifications

• Designed for use with PR-1800 Series Polythioether Sealants
• Tested with PR-1829 Series Polythioether Sealants
• Surface preparation guidance references SAE Aerospace Information Report AIR 4069
• Cleaning cloths should conform to AMS 3819

Typical Applications

• Promoting adhesion of polythioether sealants to aerospace substrates
• Application over existing polysulfide sealants before resealing
• Aircraft fuel tank sealing operations
• Aircraft structural sealing and maintenance
• Surface preparation prior to aerospace sealant application
• OEM manufacturing and aircraft MRO operations

Key Features & Benefits

• Improves adhesion between polythioether sealants and multiple substrate types
• Recommended for PR-1800 sealants applied over polysulfide materials
• Fast room-temperature drying minimises maintenance delays
• Simple one-component formulation requires no mixing
• Does not soften existing aircraft finishes
• Easy application using a brush or clean gauze
• Provides excellent sealant peel strength across common aerospace surface treatments
• Suitable for both production and repair environments

Application Guidelines

• Clean the substrate immediately before application using approved aerospace solvents.
• Remove all grease, dirt, lubricants and contaminants before priming.
• Use fresh lint-free cloths conforming to AMS 3819 during cleaning.
• Apply a thin, uniform coat by brush or clean gauze.
• Allow approximately 30 minutes drying time at standard room temperature.
• If sealing is not completed within 8 hours or contamination occurs, repeat the priming procedure.
• Follow SAE AIR 4069 recommendations for optimum surface preparation practices.

Compatibility & Limitations

• Compatible with a wide variety of aerospace substrates
• Optimised for PR-1800 Series polythioether sealants
• Recommended when applying over existing polysulfide sealants
• Must be protected from moisture during storage and use
• Discard material if it becomes cloudy

Packaging & Procurement

• Available through PPG Aerospace (PRC-DeSoto) authorised distributors
• Minimum shelf life of 9 months in original unopened containers
• Store below 27°C (80°F) in dry conditions

Why This Product is Chosen for AOG / MRO

• Improves sealant adhesion during aircraft repairs and resealing operations.
• Fast drying helps minimise maintenance downtime.
• Simple one-component application reduces preparation time.
• Compatible with existing aircraft finishes and sealant systems.
• Supports durable sealing performance in demanding aerospace environments.

Practical Suggestions for Your Team (AOG Mindset)

• Apply only to freshly cleaned surfaces using approved solvent cleaning procedures.
• Keep the container tightly closed to prevent moisture contamination.
• Do not use cloudy material, as moisture contamination may have occurred.
• Apply sealant within the recommended 8-hour window after priming.
• Always use clean, lint-free cloths to prevent contamination of prepared surfaces.

Manufacturer / Aviation Spec Codes

• Product Name: PR-187 Adhesion Promoter
• Manufacturer: PPG Aerospace (PRC-DeSoto)
• Product Type: One-component adhesion promoter
• Compatible Sealants: PR-1800 Series and PR-1829 Series Polythioether Sealants
• Referenced Standards: SAE AIR 4069, AMS 3819