It is performed on particularly greasy or encrusted parts, in order to completely remove oil and other residues deposited on the surface, as preparation for subsequent sandblasting or surface treatment. The washing process is carried out using an automatic washing machine.
The parts to be washed are neatly arranged on a parts-carrying rack and then placed inside the washing machine. Parts with blind holes must be positioned in such a way as to allow the washing water to drain, preventing the formation and stagnation of residues. Washing is carried out prior to the normal phosphating cycle.