In this paper, we present the work realized on an experimental setup which simulates in laboratory the transient phase of a lightning arc applied to aluminum samples with different thicknesses and surface coatings. A high current pulsed arc is utilized in this study, which has a peak value of 100 kA and a peak time to around 12 μs. This device is instrumented with high speed video cameras to assess the geometric characteristics of the arc attachment on the material. The shock wave generated by the arc expansion is analyzed near to the surface material, using the Background-Oriented Schlieren method. The position and velocity of the wave front and the arc root radius are determined up to 70 μs, when the lightning arc is applied to aluminum samples with different paint thickness. Finally, we perform comparisons with previous results of the hydrodynamic properties of a free arc channel subjected to the same level of current, but without the material’s interaction.