As time proceeds, partially miscible liquids spread as a cap surrounded by a primary film according to power laws, t(n), for both the leading edge (front) and the central cap. The corresponding exponents depend on the thickness, H, of the liquid aqueous substrate and the deviation of concentration from its saturation value, DeltaC = C - C-sat. As long as H is thick enough, here H greater than or equal to 5 mm, the exponents are n = 1/2 and n = 1/3 for the front and the central cap, respectively. For thinner layers, H similar to 2 mm, and moderate DeltaC, the spreading is drastically hindered and the measured values can go down to n = 0.1, due to the additional friction imposed by the confinement of the convective calls generated by dissolution below the primary film which anchor on the solid surface beneath the liquid substrate.