Abstract: In a method for removing tin from a surface and/or from a region close to the surface of a component part, the component part has a concentrated aqueous sodium hydroxide or concentrated hydrochloric acid flowing in contact with it at a temperature which is distinctly higher than room temperature. Preferably, the temperature is approximately 220.degree. C., and the component part is moreover subjected to a positive pressure of 5.5 bar. The method is suitable for a component part fabricated through the use of unidirectional solidification and liquid-metal cooling, in particular a turbine blade.