Sikagard®-831

Application by airless spray will give the best results and is recommended to achieve uniform thickness and appearance. In case of application by roller or brush, additional layers may become necessary to achieve the required coating thickness, depending on type of construction, site conditions, colour shade etc. Prior to application a trial on site may be useful to ensure the selected application method will provide the requested results.

Never dilute or mix Sikagard®-831 with any other substances.

Sikagard®-831 is commonly applied by airless spray equipment i.e. single pump equipment with a flow heater, or plural pump equipment. It could also be applied by brush or roller but these methods are only feasible for smaller areas and with compromise in application and appearance.

A suitable standard airless spraying equipment setup is as follows:

Pressure ratio: ≥ 66 : 1, flow rate: ≥ 24 l/min, pressure rate: at the spray gun ≥ 200 bar, nozzle size: 0.019 - 0.025" (0.48 - 0.64 mm), spraying angle: 20 ─ 40°

The material temperature approx. 35 °C at the nozzle outlet.

Practical hints: Remove the filter mesh (not required). Use direct material feed (without suction hose). At lower temperatures it is recommended to use insulated spray hoses (length of spray hose max. 25 m). For repairs it is required to abrade adjacent areas to a matt finish and clean off dust. Mask if necessary and then apply the Sikagard®-831.

For steel, blast cleaning is required to Sa 2.5 according to ISO 8501-1. In case of manual de-rusting use wire brushing or power tool cleaning according to ISO 8501-1 St. 3. For galvanised steel the surface must be free of dirt, oil, grease and corrosion.

In case of permanent submersion or exposure to condensation, surfaces need to be sweep blasted according to ISO12944-4.

For other surfaces tests must be carried out on the specific surfaces. For contaminated and weathered surfaces of galvanized steel or primed areas, an appropriate chemical and/or mechanical cleaning is mandatory.

Stir component A very thoroughly using an electric mixer (start slowly, then increase up to approx. 300 rpm). Add component B carefully and mix both components very thoroughly (including sides and bottom of the container). Mix for at least 3 minutes until a homogeneous mixture is achieved. pour the mixed material into a clean container and mix again for a short period as described above.

Application conditions need to be as follows: Substrate surface and ambient has to be between 10 °C and 40 °C. Optimum results are achieved at temperatures above 15 °C. Relative humidity has not to exceed 80 % and the ambient temperature has to be at least  ≥ 3 K above dew point.

If overcoating is required, the waiting time is as follows at 20 °C.

The minimum waiting time is 8 hours, whereas the maximum is 7 days for interior and 2 days for external applications.

Note: The previously applied coating must be dry and free from any dirt, moisture or contaminants that could prevent or reduce adhesion (clean if necessary). If waiting times are longer than stated, the coatings have to be reactivated by suitable mechanical and / or chemical means.

Thoroughly clean tools and equipment with Sika® Remover-208 immediately after completion or interruption of the Sikagard®-831 application process. Hands and exposed skin have to be washed immediately using hand wipes such as Sika® Cleaner-350H or a suitable industrial hand cleaner and water. Do not use solvents on skin!