Material Notes:
Dow Corning® Z-6690 Water Repellent is a solvent-free silane/ siloxane concentrate that can be diluted in organic or silicone solvents to formulate water repellents. Upon application of the diluted product, it will penetrate the substrate and provide long-term water repellency by chemically reacting with the substrate. Treated substrates become hydrophobic and retain their original appearance. Because a catalyst is present, the product can be used on neutral or alkaline substrates. Dow Corning Z-6690 Water Repellent can be used as a water-excluding prime coat for absorbent boards such as fiber-reinforced cement (FRC) boards. If post-treatment (painting) of the board is required, suitable adhesion tests should be undertaken to ensure compatibility and adhesion of the paint to the primed surface. When used with fully compatible systems, Dow Corning Z-6690 Water Repellent can work as a high-water-excluding primer/sealer coat to ensure long-life performance of the boards.Information provided by Dow Corning