Description
POLAPRIME 21
High-Performance Polyurethane Primer for Maximum Adhesion, Durability & Flexibility
POLAPRIME 21 is a solvent-based, single-component polyurethane primer engineered to deliver exceptional durability, flexibility, and long-term coating performance in demanding industrial environments. Designed for use over oxidized steel, new mild steel, and steel-reinforced concrete, it chemically reacts with the substrate to create a strong bonding layer that significantly enhances topcoat performance.
Formulated for harsh service conditions, POLAPRIME 21 improves surface integrity while maintaining flexibility to accommodate substrate movement. It strengthens weak or weathered surfaces, promotes long-term coating adhesion, and helps extend the service life of the entire protective system.
Its advanced formulation penetrates deeply into the substrate, sealing porosity and creating a uniform surface that ensures maximum adhesion and coating stability, even under extreme environmental stress.
Key Benefits
- Superior Adhesion Strength
Chemically bonds with substrates to maximize topcoat adhesion and system durability - Extreme Durability
Designed for industrial environments with long-term resistance to wear and environmental stress - Flexible Bonding Layer
Maintains flexibility to accommodate substrate movement without cracking or loss of adhesion - Corrosion Protection
Helps prevent undercutting and corrosion creep on steel and reinforced concrete - Rust Conversion Capability
Chemically converts type 2 rust, helping stabilize and protect corroded surfaces - Surface Sealing Performance
Eliminates air pockets, reducing pinholes, blistering, and coating failures - Deep Penetration
Optimized rheology ensures excellent coverage and substrate penetration - Fast Drying
Reduces dirt pickup and minimizes downtime from weather interruptions - Improved System Performance
Enhances adhesion of coatings to concrete, wood, metals, and composites - Encapsulation of Existing Coatings
Locks down well-adhered residues for improved system uniformity - Cost-Effective Primer System
High-performance formulation designed for efficiency and long-term value
Improved Adhesion to
Suitable for use over:
- Concrete and steel-reinforced concrete
- Oxidized and new steel surfaces
- Most metals
- Wood and wood composites
- Insulation systems
- Mineral composites
- Polyurethane foam (PUF)
- Glass and other approved substrates
Coverage
Approximately 300 sq ft per gallon
(Coverage may vary depending on substrate condition and porosity.)
Container sizes
1 gallon, 5 gallon
Color
Red or Gray
POLAPRIME 21 Application Guideline
Surface Preparation
All surfaces must be clean, dry, and free of dirt, loose debris, oil, grease, or any contaminants that could interfere with proper adhesion. For best results, ensure the surface is as dry as possible. Repair any damage or defects prior to application.
Application
Stir thoroughly for a minimum of three minutes with a low-speed power mixer before use. Keep the container covered whenever possible to prevent contamination.
Apply using spray, roller, or brush. Roller and brush applications are recommended for optimal penetration and performance.
- For roller application, use a medium- or short-nap roller.
- For brush application, use a natural bristle brush.
Apply only enough POLAPRIME 21 to achieve full surface coverage. Do not pour the product directly onto the substrate.
Allow the primer to dry thoroughly, then apply the appropriate surface coating as soon as possible—ideally within 36 hours—to prevent contamination. If the primed surface remains exposed for more than 48 hours, it must be cleaned thoroughly before coating.
Spray Application
Use a 30:1 airless pump with a 3/8″ hydro-resistant hose and a 17–19 tip size.
Clean-Up
Clean all tools and equipment with toluene, xylene, or another high-aromatic solvent suitable for polyurethanes.
Limitations
- Do not apply if temperatures are expected to drop below 35°F within 4 hours of application.
- Do not apply to saturated surfaces or substrates containing ice crystals.
- Do not apply if rain is forecast within 4 hours of application.
- Use EP-rated spray equipment only.
Safety Information
Before use, read the product label and Safety Data Sheet (SDS) for important health and safety information.
Keep out of reach of children and pets.
For additional information, contact the Andek Technical Department.
POLAPRIME 21 Technical Data
| VOC | 215 gms/liter | |
| Viscosity (cps) | 200 | ASTM D-2196 |
| Pounds per Gallon | 7.3 | ASTM D-1475 |
| Flashpoint | 105°F | ASTM D-3278 |
| Solids Content | 67% B.W.; 71% B.V. | ASTM D-2369 |
| Adhesion To Steel |
800 psi | ASTM D-4541 |
| Adhesion To Concrete | 400 psi | ASTM D-4541 |
| Drying Time (70°F, 70% R.H.) |
90 minutes | ASTM D-1640 |
| Hardness | 2 H | ASTM D-3363 |
| Wet Film Thickness | 5 mils | ASTM D-1212 |
| Dry Film Thickness | 4 mils | ASTM D-1005 |
| Water Vapor Transmission | 0.1 perms | ASTM D-1653 |
| Solvent Resistance | 200 M.E.K. Double Rubs | ASTM D-5402 |