7-tank process for powder coating Pre-treatment Chemicals. - The 7-tank process is a widely used pretreatment method in powder coating applications, especially for ferrous (steel) and non-ferrous (aluminum) metals. This chemical process prepares the metal surface for powder coating by removing contaminants, improving adhesion, and enhancing corrosion resistance. - Here’s a typical breakdown of the 7-tank process steps: 1. Degreasing - Purpose: Removes oil, grease, and dirt from the metal surface. - Chemicals: Alkaline or solvent-based degreaser. 2. Water Rinse (1st Rinse) - Purpose: Rinses off degreasing chemicals. - Water: Usually fresh or treated water to avoid contamination. 3. Derusting / Pickling Purpose: Removes rust and mill scale. Chemicals: Mild acid solution (like phosphoric or hydrochloric acid). 4. Water Rinse (2nd Rinse) - Purpose: Removes acidic residues after pickling. - Water: Clean or treated water. 5. Activation / Surface Conditioning (Optional but common) - Purpose: Prepares surface for better phosphating. - Chemicals: Activators such as titanium or fluoro-based compounds. # 6. Phosphating - Purpose: Converts metal surface to a non-metallic, corrosion-resistant phosphate layer. - Types: Zinc phosphate (for better corrosion resistance), Iron phosphate (simpler, lower cost). 7. Final Rinse / Passivation - Purpose: Rinses phosphated surface and may include passivators. - Additives: Chromate-free sealers or deionized water to prevent flash rusting. #7-tank process for powder coating Pre-treatment Chemicals Manufacturer.