The present invention relates to two-component polyurethane compositions which on the one hand have a long open time and, even after extended exposure to a climate with high atmospheric humidity (e.g., 70% relative humidity), even after 40 minutes and in particular even after 60 minutes, can still be glued and cured to form polymers having high mechanical strength. The composition comprises castor oil, at least one polyol having 5-8 hydroxyl groups, a mixture of two different polyether alcohols and/or polyester polyols on the basis of castor oil or soybean oil and at least one polyisocyanate. The two-component polyurethane compositions are suitable in particular for non-positive filling joints or gaps that are joined by large-surface area structural gluing, in particular of vane half shells of rotor blades for wind power plants.