In spite of the protective effect of PANI pigments, rapid proton diffusion through the modified coating exposed to NaCl solution,still causes the slight dissolution of the passive layer. This occursso fast that the polyaniline cannot repassivate the surface and con-sequently the electrochemical process on the metal surface leads to the loss of adhesion. Incorporation of silicate layers reduces in turn, the penetration of electrolyte solution through the coatings,and this reduction is more pronounced for the OMMT again due to its hydrophobic nature as compared to MMT. Therefore higher adhesion onto the substrate is expected for epoxy/PANI/OMMT as confirmed by other results in this work as well as those reported by Bagherzadeh and Mousavinejad [38].