Coal tar and bitumen modified protective paints, pigmented with aluminium flakes, are at present widely employed for the protection of steel surfaces in service conditions of high humidity and water immersion. The process of film formation is investigated for a number of paints of this class as far solvent release from films of different thickness is concerned. The aim is to determine the effect different thicknesses is concerned. The aim is to determine the effect of compositions on solvent retention; a gravimetric was employed. The resistance of the same paints against sagging is evaluated on the basis of rheological parameters. The equilibrium flow curves, structural build-up and break down kinetics are determined. The resistance to water immersion and salt fog exposure is investigated, and the role of the presence of aluminum pigment in enhancing the resistance is discussed.