Zinc Diecasting Cleaning Solution

A cleaning solution is available for brightening diecastings that have become tarnished during storage. It has the following composition:

Syrupy phosphoric acid (Sp.Gr.1.75) 60 parts by weight

Butyl alcohol (or another suitable miscible organic solvent) 20 parts by weight

Water 20 parts by weight

Wetting agent 2 parts by weight

This solution should be stored in a non-metallic vessel. The diecastings should be degreased if necessary and then immersed in the solution at room temperature for 10-20 seconds. After treatment the castings should be well rinsed and dried. They are left with a faint iridescence.