NOVELTY - Coating surface of a fiber-containing composite material with at least one organo silane anchoring agent comprises hydrolyzing anchoring agent in an acidic aqueous solution having a pH less than 3.2, and coating surface with the hydrolyzed anchoring agent.    USE - Method for coating surface of a fiber-containing composite material with at least one organo silane anchoring agent used for laminate or interconnected object of fiber reinforced composite material (claimed).    ADVANTAGE - The method provides polymer surfaces with higher adhesion strength, and may also be produced fast and with lower costs, having fewer impurities, and provides higher and more uniform adhesion strength, improved interfacial toughness and fatigue life of bonded assemblies, and no environmental pollution.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) a production of an object made of fiber reinforced composite material comprising providing organo silane anchoring agent, coating of surface of a fiber-containing composite material with at least one organo silane anchoring agent, and coating the coated fiber reinforced composite material with paint, adhesive or other surface coating;    (2) a method for improving interfacial strength of a joint of two objects made of fiber reinforced composite material, comprising providing at least one surface of joint on one or both objects with at least one organo silane anchoring agent hydrolyzed in an acidic aqueous solution having a pH less than 3.2;and    (3) a method for improving adhesion of paint on a fiber reinforced composite material or other cover for covering fiber reinforced composite material comprising providing surface of the fiber reinforced composite material with at least one organo silane anchoring agent hydrolyzed in an acidic aqueous solution having pH less than 3.2, and applying paint or other cover for covering fiber reinforced composite material.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the surface activation technology for wind turbine blade.    Glass-fiber reinforced plastic material. (GRP)