SILRES^® BS 290 CF

SILRES^® BS 290 CF is suitable for imparting water repellency to absorbent, porous, mineral construction materials, e. g.:

• brickwork
• all kinds of concrete
• aerated concrete
• sand-lime brickwork
• cement fiberboards
• mineral plasters
• mineral-based natural and artificial stone
• mineral paints
   

SILRES^® BS 290 CF is also suitable as primer for exterior paints.
SILRES^® BS 290 CF is not suitable for rendering gypsum water repellent.

Processing

Flooding, preferably not under pressure, is the best technique for applying SILRES^® BS 290 CF, which is ready to use after dilution. Apply several coats, wet on wet, until the substrate is saturated. Generally, at least two applications suffice for all substrates.

Do not leave long breaks between coats. Apply the next when the substrate has absorbed the previous one and is no longershiny (wet-on-wet working). The substrate must not have damp spots, i. e., it should look dry. The requisite quantity of SILRES^® BS 290 CF depends on the adsorbency of the substrate. The amount of hydrophobic impregnating agent required for a substrate and the effectiveness of the hydrophobic impregnation should be determined on site by testing a small area of the material to be treated.

Dilution

The solvents best suited for diluting SILRES^® BS 290 CF are aliphatic hydrocarbons (e. g. White Spirit 130/175), aromatic hydrocarbons (solvent naphtha, e. g. Shellsol A) or low-odor isoparaffin hydrocarbons (e. g. Isopar H). The solvent used should have a boiling range of 140-190°C and an evaporation number of 30-90.

If the above-mentioned hydrocarbon solvents are used, SILRES^® BS 290 CF should be diluted in a weight ratio of 1:11 to 1:15. Anhydrous alcohols, such as ethanol or 2-propanol, could also be used and are even indispensable whenever contact of the impregnating agent with solvent-sensitive materials (such as expanded polystyrene, bitumen, etc.) cannot be avoided. The alcohol must be completely anhydrous. If alcohol is used as a solvent, a dilution ratio of 1:12pbw is recommended. When impregnating slightly damp substrates, SILRES^® BS 290 CF will give better results if diluted with hydrocarbons than with alcohol.

Stir vigorously when adding the diluent to SILRES^® BS 290 CF. Since SILRES^® BS 290 CF reacts with humidity, prolonged contact with air must be avoided. The containers must be hermetically sealed.

Before applying SILRES^® BS 290 CF, be sure to cover windows and other non-absorbent surfaces properly because the product cures so quickly that it will be extremely difficult, if not impossible, to remove after a few hours. Wipe off any splashes on window panes immediately, using a solvent if necessary.