The typical problem with galvanized Iron Wire is ‘white rust’ or ‘storage stains’. It is detrimental to the galvanized Iron Wire. The durability of the zinc coating is determined by the coating weight and the stable oxide film that forms.
Zinc reaction with atmosphere occurs in two steps:
1. Zinc reacts with moisture and oxygen to form Zn(OH)2. Zn(OH)2 or “white rust” is porous and has a minor protective effect.
2. Zn(OH)2 reacts further with CO2 in the atmosphere, forming a basic zinc carbonate. This film is dense and adherent and is mainly responsible for the excellent resistance of zinc to ordinary atmospheres.
When galvanized Iron Wire is stored or transported in humid conditions that don't allow free-flowing air, only the first reaction occurs, resulting in the formation of the excessive layer of Zn(OH)2 (white rust). Usually, the damage is cosmetic. However, If unfavorable storage condition is not corrected, the formation of the white rust will continue. The reaction may consume a portion of the zinc with a subsequent reduction in the product service life.
To avoid storage of white rust the following rules must apply:
- Keep the galvanized Iron Wire dry.
- Store in the dry and well-ventilated areas.
- Avoid condensation by allowing air circulation between the surfaces.
- If stored outside: stack to provide for drainage of water. When tarp coverage is used, it must be removed periodically to allow drying and avoid condensation.