CS-309-25 – Acrylic Curing and Sealing Compound

Product Data, W. R. MEADOWS

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Non-Yellowing, Acrylic Curing and Sealing Compound

CS-309-25 acrylic curing and sealing compound is a clear, transparent, ready-to-apply, non-yellowing liquid compound formulated from special acrylic polymers and quick-evaporating solvents that effectively cures and seals freshly placed concrete.

Once properly applied, CS-309-25 provides a premium-grade film for optimum moisture retention. This produces a hard, dense, high compressive strength concrete. CS-309-25 will minimize hair-checking as well as premature cracking, dusting, spalling, and other common defects that result when concrete is not properly cured. This easy-to-use compound dries quickly and protects the concrete during construction. It resists adhesion of mortar droppings and permits easier cleanup.

CS-309-25 is ideal for application on commercial and industrial concrete surfaces, sidewalks, patios, multi-level parking decks, driveways, and parking areas … wherever you want to simultaneously cure and seal exterior concrete surfaces. The use of CS-309-25 on any exterior concrete surface provides a durable, long-lasting finish that offers improved resistance to chemicals, oil, grease, deicing salts, and abrasion. CS-309-25 provides an attractive, low sheen finish that enhances the natural appearance of the concrete.

  • Provides a totally clear membrane for new or existing concrete that will not yellow.
  • Provides a tough, durable, uniform, long-lasting film on exterior concrete surfaces.
  • Cures and seals freshly placed concrete simultaneously in one application.
  • Produces a premium-grade seal, yielding optimum moisture retention
  • Minimizes hair checking, cracking, dusting, spalling, and other defects common to uncured or improperly cured concrete.
  • Provides improved resistance to chemicals, oil, grease, deicing salts, and abrasion during construction.
  • Non-blushing, breathable film.
  • Provides an attractive sheen that enhances the natural appearance of concrete.
  • Applies easily … dries quickly for less downtime.
  • Permits easy cleanup and housekeeping … reduces floor maintenance costs.
  • VOC compliant.
1 Gallon (3.79 Liter) Cans (6 per case)
5 Gallon (18.93 Liter) Pails
55 Gallon (208.20 Liter) Drums
  • ASTM C 309, Type 1, Classes A & B
  • ASTM C 1315, Type I, Class A
  • AASHTO M 148, Type 1 Classes A & B
  • USDA Accepted
  • Complies with U.S. EPA maximum allowable VOC requirements.
May help contribute to LEED credits
  • MR Credit 2: Construction Waste Management
  • MR Credit 5: Regional Materials
300-600 ft.²/gal. (7.37-14.73 m²/L)
*Coverage may vary due to porosity and condition of concrete

When stored indoors in original, unopened containers at temperatures between 40° – 90° F (4° – 32° C), optimum performance and best use is obtained within two years of date of manufacture.

Surface PreparationExisting (Old) Concrete: Concrete surface must be clean and dry with all stains, oil, grease, dust, and dirt removed prior to application. We recommend ULTRITE DEGREASER® from W. R. MEADOWS for cleaning.

New Concrete: CS-309-25 should be applied when surface water has completely disappeared and the concrete surface will not be marred by walking workmen.

Application Method … Use a sprayer or short-nap roller to apply a uniform film. Avoid puddling in low areas. If puddles occur, brush or roll them out. A standard industrial-grade sprayer, equipped with a neoprene hose and gaskets, as well as a 5941 spray nozzle (or equivalent) is recommended for best results.

For optimum performance, apply first coat at 600 ft.²/gal. After the first coat has thoroughly dried, apply a second coat at 600 ft.²/gal. NOTE: The second coat should be applied at a right angle.

Drying Time … CS-309-25 dries quickly. Drying times may be extended depending on application rate, temperature, humidity, and project conditions. Restrict foot traffic for at least four hours. Twelve hours is preferable.

Cleanup … Application equipment should be cleaned promptly after use with xylene or toluene.

DO NOT DILUTE. FOR EXTERIOR APPLICATION ONLY. Surfaces treated with CS-309-25 may become slippery under certain conditions.

CS-309-25 should not be applied during high temperature conditions in direct sunlight. These conditions cause rapid evaporation, which does not allow the film to form properly. Under these conditions, the film may peel, bubble, and/or turn white (blush). CS-309-25 should not be applied to concrete exposed to excessive moisture. Entrapped moisture in a solvent-based sealer may cause the film to peel and/or turn white (blush).

Do not apply CS-309-25 if the temperature of the concrete is below 40º F (4º C). CS-309-25 may be used on colored concrete, but mottling may occur. Do not use on dense or non-porous surfaces, i.e. brick, stone, etc.

Concrete containing calcium chloride will remain dark longer when treated with CS-309-25. Concrete floors properly cured with CS-309-25 meet section 8.9 “Adhesion of Tile Cements” of ASTM C 1315. For other specifications, secure the approval of the paint or resilient flooring manufacturer before applying CS-309-25. The specifier and user shall determine the suitability of product for specific applications and assume all responsibility in connection therewith.

CS-309-25 is a membrane-forming sealer. All membrane-forming sealers may darken concrete or magnify imperfections caused by variations in the porosity and/or finishing of the concrete.

Prolonged inhalation of vapors in excess of permissible exposure limits may result in symptoms of transient central nervous system depression. Direct contact with the product may result in irritation of the skin and eyes. Product vapors may also cause irritation. CS-309-25 is combustible. Remove ignition sources prior to use. Empty containers may hold combustible vapors. Handle empty containers as combustible liquids. In the event of a spill, contain the product, apply absorbents and place in sealed containers. In the event of a fire, contain all run-off water. Refer to Material Safety Data Sheet for complete health and safety information.

This material last updated November 2009.


W. R. MEADOWS, INC. designs, manufactures, and markets high-quality building materials for today's construction professionals. Products are sold through an authorized distribution network. The family-owned and operated company focuses on product quality, exceptional service, and trusted integrity since its founding in 1926.
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