• Polyurethane primer for metals, concrete, wood & more
  • Chemically converts type 2 rust to prevent corrosion
  • Penetrates into crevices & pinholes to neutralize corrosion and seal against intrusion
  • Improves the cohesive strength of surfaces for maximum adhesion









POLAPRIME 21 is a solvent-based, single component polyurethane primer that is highly effective over oxidized steel as well as new mild steel and steel reinforced concrete. Chemically reacts with the substrate to promote superior adhesion of the coatings to be applied. POLAPRIME 21 is an industrial maintenance coating designed for harsh operation conditions.

Outstanding Features

  • Improves the cohesive strength of surfaces for maximum adhesion
  • Removes substrate air pockets to prevent bubbles and pinholes
  • Has rheology adjusted for optimum coverage and penetration
  • Rapid drying reduces dirt pickup and meteorological interruptions
  • Gives maximum bond performance between substrate and topcoat
  • Highly cost effective and performance designed
  • Protects against corrosion and undercutting from corrosive creep
  • Encapsulates well adhered coating remnants
  • Chemically converts type 2 rust to prevent corrosion
  • Improves adhesion of coatings to concrete, wood, and metals

Improves adhesion to

Can be used over concrete, most metals, insulation, wood composite, wood, mineral composites, PUF, glass and other surfaces.


Approximate 300 sq ft/gal, depending upon substrate

Container sizes

1 gallon, 5 gallon


Red or Gray


Preparation and Application

Surface Preparation
Surfaces must be free of dirt, loose debris, oil, grease, or other substances that would interfere with bond. It is advisable to have the surface as dry as possible. All repairs of damage or defects must be made prior to coating.

Stir thoroughly for three minutes, then keep the can covered whenever possible to prevent contaminating the primer.

Apply by spray, roller, or brush. Roller and brush techniques provide best penetration and performance results. For roller application, use a medium or short nap roller. For brush application, use a natural bristle brush. Apply enough POLAPRIME 21 only to cover the surface. It is not advisable to pour Polaprime 21 straight onto the surface. Apply the appropriate surface coating as soon as possible after thorough drying to prevent contamination of the surface, ideally within 36 hours. If the POLAPRIME 21 has been left exposed for more than 48 hours, the surface must be cleaned thoroughly to remove all dirt and contaminants.

Spray Application
Utilize a 30:1 airless pump, a 3/8″ hydro resistant hose and a 17 to 19 width tip

Clean up
Tools and equipment may be cleaned with Toluene, Xylene, or any high aromatic solvent suitable for polyurethanes.

Do not apply POLAPRIME 21 if the temperature is predicted to drop below 35°F within 4 hours of completion of application. Do not apply any of the POLAPRIME 21 to saturated surfaces or substrates that have ice crystals entrapped. Do not apply if rain is forecast within 4 hours of completion of application. Use EP rated spray equipment.

Read the container label warning and Safety Data Sheet (SDS) for important health and safety information prior to the use of this product.


For additional information, contact the Andek Technical Department


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

Additional information


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