Surface PreparationConcrete and other similar cement based surfaces, such as sand and cement screed, should be clean and reasonably dry, slight dampness is acceptable. A good sweep and/or vacuum is often sufficient on a dusty or slightly dirty surface.
Watco Bio D may be used to remove dirt, light grease and oil. Watco Bio D may be diluted with two parts cold water when removing light contaminates. Avoid wetting very porous surfaces since they will absorb too much water. Vacuum shotblasting is an ideal method for cleaning and preparing large areas of concrete.
New concrete should be left for at least 14 days in reasonable drying conditions. Any laitance (a weak, dusty layer on new concrete) should be removed by stiff brushing (or shotblasting on larger areas). Do not acid etch surfaces prior to using Watco Concrete Stain.
Mixing
Shake the can well and then thoroughly stir the contents using a spatula, wooden batten or similar wide bladed tool to stop the pigment from settling.
Application
Use a brush or soft broom (not a roller). Pour a little of the product at a time directly onto the substrate and spread using the brush or broom. Work the liquid well into the substrate. Apply more if the liquid rapidly disappears into very porous substrates. Do not allow the liquid to pond on the surface. One application is generally sufficient to produce a subtle, low level tint.
To achieve a darker, bolder tint, simply add another coat/s allowing at least 6 hours between coats in reasonable drying conditions. Stains are semi- transparent colours and may leave an uneven finish due to the variable nature of the substrate.