BOYSEN® Plexibond™ #7760 is a specially formulated acrylic polymer designed for compounding with pozzolan or Portland cement. The resulting mixture possesses excellent adhesion, water resistance and flexibility even on thin section applications. Its use eliminates cement plastering defects and water seepage, making it ideal for waterproofing roof decks and firewalls. It makes a durable and decorative cementitious coating that not only enhances the appearance of light building materials but also prolongs their service life. It offers excellent corrosion resistance when applied on metal surfaces, and can also be used to improve adhesion to mortar patching and tile grout.
1. BOYSEN® Plexibond™ #7760 should be applied on bare concrete, wood, or metal NOT PREVIOUSLY PAINTED.
2. Surface should be clean, free from oil, grease, dirt, any loose grit or mortar. Wet Masonry surfaces first with water before applying mix to avoid abrupt drying and cracking of the applied modified cement, especially under hot and sunny conditions.
Preparation of Mixture:
1. Mix 6.5 to 7.5 kgs. of cement to 4 liters of BOYSEN® Plexibond™ #7760.
2. To prevent lumping, add cement to Plexibond slowly while stirring.
3. Pass mixture through a fine strainer to sift out lumpy materials.
4. Ensure intimate mixing, stirring as often as possible to avoid settling. Mixture proportion should be kept constant for a uniform texture.
5. Mix only enough material to prevent waste. Workability of BOYSEN® Plexibond™ mixture is 30 minutes, while pot life is 2 hours.
For vertical surfaces:
1. Apply 2 coats of the BOYSEN® Plexibond™ mixture by textured roller (orange peel texture) while maintaining coverage rate at 5 -6 sq. meters per gallon.
2. Orange peel textured finish can also be achieved by applying on coat by brush and a second by mortar gun. Recoating interval is 1 to 2 hours.
For horizontal surfaces:
1. Apply 3 coats by textured roller.
2. Reinforce joints, corners, and active cracks susceptible to cracking or movement with a strip of fiberglass matting.
3. Put on the matting immediately after the second coat, while the mixture is still wet. The matting should adhere to the mixture.
4. Make sure the BOYSEN® Plexibond™ mix and the matting is completely dry before applying succeeding coats.
5. The matting should be completely should be completely covered by the mixture.
6. Let dry for one day then apply a bond coat by brushing BOYSEN® Plexibond™ straight from the can prior to laying out mortar topping.
For filling large cracks:
1. Add 3 parts by volume of fine uniform-sized sand to 1 part cement and mix with BOYSEN®Plexibond™ to trowellable consistency.
1. The effectiveness of BOYSEN® Plexibond™ as waterproofing is limited to water coming from positive side (water ingress above the coated part of the substrate) and not from the negative side (water coming from the back of the coating applied on the substrate).
2. The cementitious coating will be able to cover hairline cracks but will not bridge gaps and active structural cracks. Immediate repairs using suitable sealants should be done.
For maximum durability, paint application is recommended. Allow BOYSEN® Plexibond™ to dry at least one (1) day before paint application. Suggested painting systems are:
1. BOYSEN® Wallguard™ – dirt – resisting water – based acrylic finish
2. BOYSEN® Acrytex™ – watertight acrylic solvent based finish
3. BOYSEN® Permacoat™ Latex – acrylic water-based latex finish
4. BOYSEN® Acqua Epoxy™ – acrylic water – based epoxy finish