Group of the agents Pragokor Seal Cu, Fe and Zn comprises water-borne varnishes convenient predominantly for the finish coating, sealing and preservation of the metallic surfaces or conversion coatings. In particular cases, they may be used as an irremovable inter-machinery operations protection against corrosion. They create thin polymeric colourless and transparent layers bearing both versatile and specific corrosion inhibitors, hydrophobic and preservation additives and other modifying substances. The polymeric layer, together with corrosion inhibitors, will create both mechanical as well as chemisorption barrier against the adverse activity of corrosion stimulators. The Pragokor Seal agents should be applied by dipping technique only as the last technological operation just before drying, after the last rinsing step. They may be alternatively applied for the clean and dry surfaces, the surface must be, anyway, wettable with water.