MasterKure HD 300WB: Concrete Hardener and Dustproofer

  • Formerly known as Lapidolith
  • Hardens and densifies concrete floors to reduce absorption and prolong service life
  •  100% reactive with the free lime in concrete to produce a dense, abrasion-resistant yet breathable surface
  • Tightly binds together the cement, sand, and aggregate for improved chemical resistance
  • Non-film forming, resulting in reduced cleaning and maintenance costs
  •  Compatible with most resilient tile adhesives
  • For coverage rates please refer to data sheet below

Product Data Sheet

Safety Data Sheet

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MasterKure HD 300WB: Concrete Hardener and Dustproofer

MasterKure HD 300WB is a magnesium fluorosilicate concrete hardener and dustproofer that bonds chemically with the concrete to strengthen and harden floors that are porous, readily absorptive, and only moderately hard.

Surface Preparation:

  1. New concrete should be cured per ACI 308 Guidelines. For best results, allow concrete to air dry for at least 72 hours. Concrete should be at least 10 days old and preferably 28 days old before application of MasterKure HD 300WB.
  2. Surfaces must be clean, dry, and free of contaminants, including carbonation byproducts.


  1. The number of applications and dilution ratios for MasterKure HD 300WB are dependent on the porosity and density of the concrete. Refer to coverage chart. Two applications of MasterKure HD 300WB are generally required
    on concrete and non-resin-based terrazzo floors. Wood-floated, broom-finished, or porous floors may require a third application of product at full strength.
  2. Apply MasterKure HD 300WB by roller, spray, brush, or squeegee. Bubbling indicates reaction of MasterKure HD 300WB with the concrete. Distribute evenly and mop up excess solution or puddles.


1. After the first application, allow the floor to dry until no longer visibly wet.
2. If crystals develop during the second application, flush the surface liberally with clean water. Use hot water if available. At the same time, rapidly brush the floor with a stiff bristled broom.
3. Mop up excess water and allow the surface to dry.

Concrete, Polished Sheen:

  1. To achieve the appearance of a polished sheen, use 3 applications of MasterKure HD 300WB. See Yield Chart for dilution ratios of each coat.
  2. As the last application is drying, wait for the uniform appearance of white crystals. Flood the floor with water and buff with a commercial floor buffer using an abrasive pad. Continue buffing until the floor acquires a patina or polish and the whiteness is gone.
  3. The above recommendation is for dense, steel troweled floors. Older or more porous concrete may require a stronger mix, lower coverage rate or more than three applications. Caution: unusually wet or oily environments will be more slippery with this surface treatment.

Terrazzo (Non-Resin-Based):

  1. Do not allow the first application to dry. While the surface is still damp, flush it thoroughly with clean hot water and then allow it to dry until no longer visibly wet. For the second application, follow the same procedure but mop up excess
    wash water and allow the surface to dry.
  2. The appearance of white crystals after the first or second application indicates that the mix may be too strong, or that the surface has reached maximum hardness. If this occurs, stop the application and flush the surface with clean, hot water; scrub with a stiff-bristle broom, and allow to dry. Increase the dilution for any remaining applications to minimize crystal formation.

Clean Up:

Clean all tools and equipment with water immediately after use. Thoroughly flush sprayers. Dispose of unused material according to local regulations.


  1. . Routine sweeping and washing of floors with mild conventional cleaners and detergents is recommended.
  2. Remove all abrasive grit and wipe up corrosive spills as soon as possible.

Material Safety Data Sheet

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Weight 20 lbs
Dimensions 30.48 × 30.48 × 38.1 in