Large quantities of bonding pastes are used in the manufacturing of wind turbine rotor blades. The normal production procedure is to manufacture the upper and lower shell of the rotor blade shell in separate molds and glue them together by the bonding pastes. These bonding pastes must have good thixotropic and specific slump properties. That is why AEROSIL® fumed silica are used as standard thixotropes in bonding pastes based on epoxy, polyurethane and vinylester resins. The hydrophobic fumed silicas AEROSIL® R 208 and AEROSIL® R 202 are high-performance thixotropes used in bonding pastes for the manufacturing of rotor blades. Furthermore, bonding pastes must also possess excellent fatigue properties. Structure-modified fumed silica grades like AEROSIL® R 7200, AEROSIL® R 8200, and AEROSIL® R 9200 can adjust bonding pastes with excellent reinforcing properties. Organofunctional silanes like Dynasylan® GLYMO, Dynasylan®AMMO, Dynasylan® 1124, and Dynasylan® 1146 act as adhesion promoters in bonding pastes, and they can further improve the crosslinking density of suitable bonding pastes.