Anyone who has experienced and resolved tarnishing of Aluminium surface upon cleaning with DI water + saponifier. The aluminium surface is protected with conversion coating which is turning blackish when exposed to saponifier solution. Try distilled water. Conversion coatings are very nice paints that allow other paints to stick to aluminum, Saponifiers are alkaline and have a pH >. It’s a well dI water is so corrosive it can’t be used in iron pipes, and will certainly tear into aluminum. DI water has high free hydrogen ion concentration and so, is VERY corrosive. It is alodine 120X and Iridite ’14 2′ are good conversion coatings. Your conversion coating wouldn’t do dip about preventing corrosion of the aluminum surface when soaked in saponified DI water. Type 1 coatings are thicker than Type 3, that are whisper thin. Straight air will work but you will get into ESD problems that you don’t seek for! It’s a well dave is absolutely right! I’d say in case so this can definetly exacerbate the huge poser, DI water left on Parts after wash and rinse.
You can try to remove excess DI water by using a IONIZER air source to blow off any water.