During exploitation, the properties of the epoxy coating deteriorate and therefore, it is necessary to modify it with metal particles. In this paper, spherical aluminium nanoparticles (Al NP) of 100 nm with 99.9% purity were used to modify the epoxy coating for the better corrosion protection of grey cast iron. Pure Al has a high corrosion resistance and can form a thin protective film that prevents its further oxidation, thus, becoming inert and environmentally friendly. To examine these facts, different concentrations (0.5, 0.75, 1.0, 3.0, and 6.0 wt.%) of Al nanoparticles were dispersed in the epoxy coating. The surface of the modified nanocomposite coating was analysed using scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS). Furthermore, the physical properties such as colour, thickness, hardness, and adhesion to the cast iron surface were tested as well. The same properties were tested by exposing the sample plates to corrosive conditions in the climate chamber. Their anticorrosion properties were investigated using electrochemical impedance spectroscopy (EIS) by their immersion in 3.5 wt.% NaCl solution as a corrosive medium. The coating with 0.75% Al NP showed the best corrosion resistance after 10 days of exposure in salt water, while the sample with 1.0% Al NP showed the best corrosion resistance after exposure to the icing/deicing process.