Optimizing Drying Temperature in Hot Dip Galvanizing to Prevent White Rust

Hot dip galvanizing is a highly effective method for protecting steel from corrosion. However, improper storage and transportation conditions can lead to the formation of white rust, especially when galvanized parts are stacked closely together. To minimize this issue, maintaining a low-humidity environment and ensuring proper ventilation between stacked components are essential. Below are key preventive measures to consider.

1. Surface Treatments to Reduce White Rust

The need for post-galvanizing treatments in hot dip galvanizing largely depends on the shape of the parts and storage conditions. Tightly stacked or nested components are more prone to white rust, particularly if stored for several weeks.

· Paints & Clear Coatings: Hollow structures like galvanized pipes can be coated with a clear lacquer after hot dip galvanizing.

· Oils & Waxes: Wire, sheet, and mesh products benefit from waxing or oiling.

· Chromate-Free Passivation: Structural parts can undergo passivation immediately after water cooling.

If galvanized parts are to be installed quickly, post-treatment may not be necessary. However, if painting is required within six months, choosing a compatible treatment is crucial to ensure proper paint adhesion.

2. Proper Storage Conditions

Galvanized parts should be stored in dry, well-ventilated covered areas. If outdoor storage is unavoidable:

· Elevate parts above the ground using spacers to allow airflow.

· Stack parts at a slight angle to facilitate drainage.

· Avoid direct contact with damp soil or decaying vegetation.

3. Handling During Transportation

During shipping, temperature fluctuations can cause condensation, increasing white rust risk. Key precautions include:

· Using spacers to separate parts and improve air circulation.

· Avoiding pine wood (which contains corrosive resins) and opting for untreated, dry wood like poplar or fir.

· Sealing small parts with desiccants in containers to absorb moisture.

4. Avoiding Moisture Exposure

Galvanized parts should never be stored where they may be exposed to rain, fog, condensation, or snow.

5. Special Considerations for Marine Transport

When shipping hot dip galvanized steel by sea:

· Avoid placing parts as deck cargo or in bilge areas where seawater exposure can accelerate corrosion.

· Ensure proper ventilation, especially in tropical climates with high humidity.

Conclusion

Controlling the drying temperature and environment after hot dip galvanizing is critical to preventing white rust. By implementing proper storage, handling, and surface treatments, manufacturers can ensure long-lasting corrosion protection for galvanized steel products.

For superior durability, consider our high-quality hot-dip galvanized pipes—engineered to resist corrosion even in harsh environments. Contact us today to learn how our solutions can meet your project needs!

For more insights on hot dip galvanizing best practices, stay tuned to our blog!