🟧 Introduction

Once anodizing is complete, aluminum’s surface transformation isn’t over.
 The final step — sealing — determines how well the anodized layer resists corrosion and retains its color over time.
It’s essentially the invisible armor that preserves both performance and appearance.

🔹 What Is Sealing in Anodizing?

During anodizing, the aluminum oxide layer forms with thousands of microscopic pores.
 While these pores allow for dye absorption, they can also let in moisture and pollutants.
 The sealing process closes these pores, locking in color and strengthening the surface.

🔹 Main Types of Sealing

1. Hot Water Sealing:
   The anodized parts are immersed in hot water (95–100°C), transforming the oxide into a hydrated, stable form that naturally seals the pores.
   🔸 Ideal for architectural and outdoor applications.
2. Nickel or Cobalt Sealing:
   A chemical bath containing nickel or cobalt salts forms an extra protective barrier.
   🔸 Enhances corrosion resistance and color fastness, especially for dark finishes.
3. Cold Sealing:
   Conducted at lower temperatures (25–30°C) using fluoride-based compounds.
   🔸 Energy-efficient and fast, but requires precise chemical control.

🔹 Benefits of Proper Sealing

• Prevents moisture and contaminants from penetrating the oxide layer.
• Maintains color consistency and brightness over time.
• Boosts corrosion and abrasion resistance.
• Makes surfaces easier to clean and maintain.
• Extends the lifespan of aluminum in harsh environments.

🟩 Conclusion

Sealing is more than just a final step — it’s the key to long-lasting anodized quality.
At Golden East for Trade & Industry, we apply multiple sealing methods — both thermal and chemical — in compliance with ISO 7599, ensuring aluminum that lasts beautifully and performs flawlessly.
✨ Golden East – Precision in Every Detail.