Bonding Agent - For Concrete (LN-520)

This flexible concrete bonding agent increases the adhesion of fresh concrete over existing concrete, and can be used as an additive in mixtures of mortar, concrete or plaster. It is non-flammable, and can get the job done right inside or out.


Bonding Agent - Concrete Adhesive

Key Features

Recommended For

To increase the adhesion of mortar, concrete or plaster mix

NOT Recommended For

Repairs thicker than 19 mm (3/4 in.). Consult our services before using with any other product.

Available Sizes

  • 946 mL
  • 3.78 L


  • 946 mL quart covers 1.5 square metres (15.7 square feet) As an additive for mortar for a thickness of 6 mm (1/4 in).
  • 946 mL quart covers 3.7 square metres (39.0 square feet) As an adhesive.
  • 3.78 L gallon covers 6.0 square metres (64.0 square feet) As an additive for mortar for a thickness of 6 mm (1/4 in).
  • 3.78 L gallon covers 15.0 square metres (162.5 square feet) As an adhesive.

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Wet product: Soap and water.
Dry product: Scraper and mineral spirits.


Between 15°C (60°F) and 30°C (85°F)

Surface Preparation

Materials, adhesive and room must be maintained at a temperature of 15°C (60°F) to 30°C (85°F). Surfaces should be clean and free from all contaminants. Stir thoroughly before use. Concrete: Concrete surfaces must be thoroughly cleaned. They must show no signs of curing agent that can interfere with adhesion. The surface should not be brittle, soft or fragile. All concrete surfaces must be completely free of efflorescence salts, moisture or hydrostatic pressure. After the cleaning, let the concrete dry for 24 hours. The concrete temperature should be above 5°C (40°F). Check for efflorescence salt. If necessary, treat the surface with a solution of 5 to 10% muriatic acid (hydrochloric) or other acidic solution provided for this purpose. Leave on for 20 minutes or according to the product instructions. Rinse several times with water and allow it to dry thoroughly (at least 24 hours).

Product Application

As an adhesive: Apply the product followed immediately with the mortar. As an additive for mortar: Use 925 mL of product for 4 kg of cement and 9 kg of clean dry sand. Mix half and half LIQUID NAILS LN-520 and water. Slowly add the premixed cement with the sand. Never add the liquid to the powders. If the mixture is too thick, add a small amount of water. Always apply on a damp surface or on a surface covered with LIQUID NAILS LN-520. Level the concrete within 30 minutes. Humidify the surface within the fist 24 hours. Note: On materials other than concrete, surfaces must be covered with LIQUID NAILS LN-520.

Working Time

As an additive, level concrete within 30 minutes.
As an adhesive, coat within 10 minutes.
Fully cures within 28 days.

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Price and item availability may vary.