TT-P-645B (1-gal-Tin)

TT-P-645B Zinc Molybdate Primer (AMS 3117)

Overview

TT-P-645B Zinc Molybdate Primer is a one-component, alkyd-based corrosion-inhibiting primer formulated for use on steel and properly prepared aluminium surfaces. It is designed to provide a durable protective base coat with strong corrosion resistance and good adhesion for subsequent coating systems. The product is pigmented with zinc molybdate and is compliant with both government and aerospace specifications.

Key Technical Specs

• Product Type: One-component alkyd corrosion-inhibiting primer
• Pigment: Zinc molybdate
• Solids (Weight): ≥ 78.8%
• Solids (Volume): ≥ 56%
• Weight per gallon: 13.3–13.7 lb
• Colours: Yellow or Green
• VOC: Low / high solids system
• Shelf Life: 12 months

Drying & Cure Schedule

• Dry to touch: ≤ 6 hours
• Recoat window: 6–8 hours
• Full cure: up to 14 days

Approvals & Specifications

• TT-P-645B Government Specification
• AMS 3117 compliant

Typical Applications

• Corrosion protection for steel structures and components
• Primer for aluminium and non-ferrous metals (with pretreatment)
• General industrial and aerospace maintenance coatings
• Base coat for multi-layer protective paint systems

Key Features & Benefits

• Strong corrosion-inhibiting zinc molybdate pigment system
• High solids formulation for improved film build
• Suitable for ferrous and non-ferrous substrates
• Fast drying for operational efficiency
• Meets aerospace and government coating standards

Surface Preparation

• Surface must be clean, dry, and free of oil, grease, and contaminants
• Clean steel in accordance with SSPC-SP-1 standards
• Light sanding recommended for most metals
• Aluminium requires pre-treatment wash primer (MIL-C-8514C)
• Remove oxidation and loose material prior to coating

Application Guidelines

• Apply by spray, brush, or roller
• Spray application: thin with approved solvents (xylene or MIL-T-81772B TY.III) as required
• Brush/roller: apply at supplied viscosity
• Apply wet coat to ensure adhesion and corrosion protection

Compatibility & Safety Notes

• Flammable product – handle with care
• Use in well-ventilated areas
• Avoid skin and eye contact
• Refer to Safety Data Sheet before use

Why This Product is Used

• Reliable corrosion resistance in industrial environments
• Compatible with aerospace-grade coating systems
• Strong adhesion to properly prepared metal substrates
• Suitable for both maintenance and manufacturing applications

Practical Suggestions for Application Teams

• Ensure correct surface pretreatment on aluminium before application
• Maintain correct film thickness for optimal corrosion protection
• Respect recoat windows to ensure intercoat adhesion
• Use controlled ventilation during application due to flammability