Description: The sample is placed into a cylindrical volume, where it is wetted axially from one end using pressurised water. The total volume of the sample remains constant throughout the experiment. Results include bentonite water content as a function of axial position and time. Additionally, the water content has been converted to the degree of saturation by assuming a grain density of $\pu{2.78 g/cm^3}$. Approximately $\pu{1.2 mm}$ layers from both ends of the sample are rejected due to the uncertainties in the displacement measurements. The image data from the initial state was corrupted and cannot be used for analysis. The density analysis was conducted backwards in time, assuming full saturation at the end of the experiment. The average initial water content (time = 0 h) of the bentonite powder is provided in the data.