The removal of crystalline scale deposits from stainless steel surfaces has been studied experimentally using dilute solutions of hydrochloric acid to remove thin layers of calcium carbonate (calcite) in a purpose built flow cell. The initial linear removal rate decreased rapidly after a point which corresponded to the appearance of scale-free patches on the metal surface. Modelling the removal rate required reliable values of the surface-liquid mass transfer coefficient, which were obtained from heat transfer measurements. Modelling studies indicated that diffusion of H+ was the rate controlling step for the range of Re considered (2000 < Re < 5000). The overall cleaning behaviour was found to be dominated by the roughness and non-uniformity of the deposit.