Gas shield electric arc coating of carbon steel surface is considered in relation to repair applications. Two types of wires are incorporated in the experiments including standard and nano-particle blended. The coating structure and the metallurgy are examined using the Scanning Electron Microscopy (SEM), and Energy Dispersive Spectroscopy (EDS). The microhardness of the resulting coating is measured and compared with the results obtained from the conventional wire. It is found that fine structures are formed in the coating due to the presence of nanoparticles. In this case, microhardness increases significantly in the coating.