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Technical Dayta Sheet Compedium

CONTENTS CONCRETE REPAIR CORROSION CONTROL GROUTS & ANCHORS PROTECTIVE COATINGS INDUSTRIAL FLOORING SURFACE TREATMENTS JOINT SEALANTS CONCRETE JOINTING JOINT FILLERS WATERPROOFING WATERSTOPS ROOFING TIMBER FLOORING ALPHABETICAL INDEX ® Water seepage All water seepage must be stopped using Vandex Plug prior to the application of Vandex BB75-Z. Do not attempt to apply BB75-Z over weeping or seeping substrates no matter how slow the seepage, as the BB75-Z will be damaged by the seepage water before it has a chance to cure. Application instructions Vandex BB75-Z is supplied in the form of a dry powder and can be applied as a slurry by trowel, brush or spray. To mix, place 25 kg of Vandex BB75-Z into a clean container and add 5 - 5.75 litres of clean tap water for brush or trowel application. Add 5.75 - 6.25 litres of water for spray application through a Vandex Hopper Gun. The Vandex BB75-Z powder and water must be thoroughly mixed using a slow speed electric drill (300 rpm) or Festo type mixer fitted with a grout mixing paddle (PC 770163) for 3 minutes immediately prior to use. Mix only as much material as can be used in 20 minutes and stir the mixture frequently. If the mixture starts to set, do NOT add more water, simply stir the product to restore workability. Ensure that all surfaces to which Vandex BB75-Z will be applied are pre-watered. The correct amount of pre-watering is measured by the substrate taking on a greenish appearance, however there must be no free surface water. A simple check can be performed by placing a hand on the pre-watered substrate and removing the hand. If the hand is wet from contact with the substrate, then the substrate is too wet and must be allowed time for the excess surface water to evaporate. Surfaces that have been pre-watered and dry out before application of the Vandex BB75-Z must be prewatered Page 3 513 again. Apply the first coat from the base of the wall and work towards the top using a trowel, a hopper gun or a plasterer’s brush in a horizontal brushing action. After 4 - 5 hours apply the second coat ‘green on green’ so that a chemical bond is achieved between the two coats. Do not apply more first coat during a day’s work session than can be overcoated with a second coat during the same day. When applying Vandex BB75-Z by spray using a Vandex Hopper Gun, ensure that the gun is held directly perpendicular to the surface at a distance of about 500 mm to ensure that the maximum impact energy is applied to the surface and to prevent any shadowing across small surface imperfections. After application of the first coat by spray, brush or trowel the wet surface to remove any entrapped air. When applied by Hopper Gun, Vandex BB75-Z produces a very smooth ‘orange peel’ finish after application which may be too smooth for the bonding other coatings, tile mortars or finishes. If other products are to be applied over Vandex BB75-Z, roughen the surface slightly by brushing or brooming the surface of the BB75-Z while it is still wet, or alternatively, seed the Vandex surface with sand while it is still wet. The cure time of Vandex BB75-Z is affected by both temperature and humidity. Humidity has an influence on waiting times between coats and resistance to rain. Ensure that the freshly applied BB75-Z is protected from rain for the first day, and the drying effects of the sun and wind during the first 5 days of cure. In most waterproofing applications, Vandex BB75-Z is applied in two coats by brush, trowel or spray. Specific minimum application rates are as follows; Ground moisture - one coat by brush, trowel or spray at an application rate of 3.0 kg / m² / coat. (Total minimum layer thickness for one coat must be 1.5 mm). Pressureless surface water - two coats by brush, trowel or spray at an application rate of 2.0 kg / m² / coat. (Total minimum layer thickness for two coats must be 2.0 mm). Water under pressure - two coats by brush, trowel or spray at an application rate of 3.0 kg / m² / coat. (Total minimum layer thickness for two coats must be 3.0 mm). Curing and protection Surfaces treated with Vandex BB75-Z must be kept damp and must be protected from the drying action of direct sunlight for a minimum period of 5 days after application. Protect all treated surfaces from wind and frost, by covering with damp hessian and plastic sheeting or equivalent. Cleaning Tools and equipment should be cleaned with water immediately after use. Limitations Vandex BB75-Z is suitable for use in open headed sewerage processing tanks. Consult Parchem for specific advise on the use of Vandex BB75-Z in closed sewerage environments where sulphuric acid concentrations may be high. In negative side applications, do not apply Vandex BB75-Z to substrates that are weeping. Use Vandex Plug to stop all water seepage before applying BB75-Z. Note: Vandex BB75-Z is a rigid coating and as such will not accommodate any movement due to cracks or joints in the substrate beneath; in such applications an elasticised product such as BB75E-Z or Cemelast should be considered. Vandex® BB75-Z


Technical Dayta Sheet Compedium
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