15. What is the white rust of galvanized layer? How to prevent and remove it?

When condensation water adheres to the zinc coating surface and interacts with oxygen, carbon dioxide, hydrogen sulfide, sulfur dioxide, chemical compounds, soot particles, dust, and other chemical gases, it forms a corrosive aqueous solution. This solution adheres to the zinc layer, creating an electrolyte that triggers electrochemical corrosion with the chemically unstable zinc layer. The result is the formation of powdery corrosion products known as "white rust".