What is the 7-Tank Process in Powder Coating?
- The 7-Tank Process is a chemical pretreatment system used to clean and prepare metal surfaces—primarily mild steel—before applying powder coating. It removes oil, rust, and scale, and forms a phosphate layer that improves adhesion and enhances corrosion resistance.
1) Degreasing
Removes oil, grease, and dirt from the surface.
2) Water Rinse 1
Rinses off degreasing solution.
3) Derusting / Pickling
Removes rust, mill scale, and oxides using acidic chemicals.
4) Water Rinse 2
Cleans off the rust remover.
5) Surface Activation (optional)
Sometimes used to prepare surface for better phosphating.
6) Phosphating
Deposits a conversion coating (zinc or iron phosphate) that increases corrosion resistance and paint adhesion.
7) Final Rinse (with or without Passivation)
Neutralizes remaining chemicals and may include a passivation agent to further prevent corrosion. #7-Tank Process in Powder Coating Manufacturer
