Sauereisen Inc.

- Model No. 381 - Aromatic Polyurethane Lining



Sauereisen ConoFlex Urethane No. 381 is an aromatic polyurethane lining that provides excellent flexibility and impact resistance for concrete, steel, and other substrates. No. 381 is a chemically resistant lining combining toughness, elongation, and low permeability with a fast cure time. Typical uses: flexible lining for various applications, including primary/secondary containment structures subject to movement, tank coatings and linings, cooling tower basins, and food processing areas (FDA & USDA compliant).

  • Chemically resistant - withstands a wide range of acids and bases
  • Highly impermeable - eliminates corrosion of substrates
  • Flexible - moves with substrate
  • Impact and abrasion resistant
  • 100% Solids
  • High-build characteristics
  • Color: Dark Gray 53
  • USDA BioPreferred based on high content of renewal materials

Temperature of Working Area
Maintain a temperature of 50°F - 90°F on air, substrate, liquid and hardener components during mixing, application, and curing for optimum results. Ambient temperature must be at least 5°F above dew point.

Applications in direct sunlight and rising surface temperatures may result in blistering of the material due to expansion of entrapped air or moisture in the substrate. Concrete that has been in direct sunlight must be shaded for 48 hours
prior to application and remain shaded until after the initial set. When the surface temperatures are rising, it may become necessary to postpone the application and to apply the materials when temperature of the substrates are decreasing.

Surface Preparation
All surfaces must be made free of oils, grease, water, and other contaminants that may inhibit the bond.

Metal: Abrasive blast to a minimum 3-mil profile employing a near white metal SSPC-SP10 finish, in accordance with Nace 2 specifications. All welds must be continuous, free of flux, and have a smooth rounded radius without any sharp edges or protrusions.

Prepare concrete surfaces in accordance with SSPC-SP13/NACE 6 'surface preparation of concrete' for detailed guidelines.

ConoFlex Urethane No. 381 should be used in conjunction with ConoPrime No. 502.

New Concrete - All structures must have the necessary strength to withstand imposed loads during normal use and operation. After ConoPrime No. 502 is applied, the surfaces should be floated with Sauereisen Urethane Filler Compound No. 309 to fill all voids and depressions.

Substrates must be free of oil, grease, and other contaminants that may inhibit bond. This can be achieved by chemical
cleaning. Abrasive blast, or high-pressure water blast to remove laitance and to obtain a uniform surface texture exposing fine aggregate resembling coarse sandpaper.

Old Concrete - Concrete must be dry, firm and must have the necessary strength to withstand imposed loads during normal use and operation.

Surfaces must be free of oil, grease, and other contaminants that may inhibit bond. This can be achieved by chemical cleaning. Mechanical methods should be utilized to remove laitance, old paints, protective coatings, and attacked or deteriorated concrete.

For concrete substrates, abrasive blast or high-pressure water blast to obtain a clean, uniform, and sound substrate. All structural cracks should be repaired. All slopes should be reestablished.

For irregular surfaces with voids exceeding 1/4 inch, Sauereisen Substrate Resurfacer No. F-121 may be used as an underlayment for ConoFlex No. 381.

Prior to application of ConoFlex No. 381, inspect the primed surface for voids, bubbles, and other defects that may result in blistering or pinholes. Repair as necessary to ensure a sealed surface.

Other Surfaces: Conoflex No. 381 may be used as a coating or lining over other substrates. Please contact Sauereisen for technical assistance.

Contact Sauereisen for technical assistance.

Mixing / Installation
Premix No. 381 Part B Resin component to assure even dispersion of pigment.

For applications by plural component spray equipment:
Apply ConoFlex Urethane No. 381 with a GracoTM 'Hydra-Cat' with a King Air- Head or Gusmer 20/35, set to spray at a fixed volumetric ratio of 3:1. Use GracoTM R-A-C IV spray tips in sizes from 0.021 to 0.043.

ConoFlex Urethane No. 381 can also be applied by roller, trowel, or squeegee. Consult Sauereisen for specific details.

It is very important to use a NIOSH-23C approved respirator when spraying ConoFlex Urethane No. 381. Please consult No. 381 SDS for proper personal protective equipment.


Theoretical coverage is 26.7 ft2 per gallon at 60 mils.


All equipment should be cleaned with MEK before material cures. If removal is required after cure, consult Sauereisen.


If Sauereisen ConoPrime No. 502 is used, please refer to the ConoPrime No. 502 data sheet for curing and top coat

  • Abrasion Resistance (ASTM D4060,CS-17)-(1,000 gms/1,000 cycles): 45 mg
  • Adhesion to Steel (ASTM D4541): 2,940 psi
  • Elongation at Break (ASTM D412): 41%
  • Flexibility (ASTM D 1737) 30 mils: 180° over 0.125 in. Mandrel
  • Hardness Shore D (ASTM D2240-86) 68 +/- 3
  • Mixing Ratio 3:1 - Resin to Activator
  • Moisture Vapor Transmission (ASTM F1249-06): 35-40 mils: 0.012g/100 in2
  • Percent Solids: 100%
  • Pot Life: 12-15 minutes
  • Service Temperature Dry:
    • Continuous:-40°F to 200°F
    • Maximum Surge: 350°F
    • Immersion: Insulated: 150°F
    • Non-Insulated: 120°F
  • Tensile Strength (ASTM D412): 2,775 psi
  • Volatile Organic Compounds (VOCs): 0.0 g/L

Physical properties were determined on specimens prepared under laboratory conditions using applicable ASTM procedures. Actual field conditions may vary and yield different results; therefore, data is subject to reasonable deviation.

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