Seven Tank Process Chemicals
- The Seven Tank Process is a standard procedure for pre-treatment of metal surfaces before painting or coating. This process involves a sequence of chemical treatments to clean, degrease, and provide a protective layer to ensure proper adhesion of the subsequent coatings. Here is an overview of the typical seven stages and the chemicals used in each:
1. Degreasing (Alkaline Cleaning):
. Chemicals: Alkaline degreasers or detergents
. Purpose: Remove oil, grease, and other contaminants from the metal surface.
2. Water Rinse:
. Chemicals: Freshwater
. Purpose: Rinse off the alkaline residues from the degreasing stage.
3. Pickling (Acid Cleaning):
. Chemicals: Dilute acids (usually phosphoric acid or sulfuric acid)
. Purpose: Remove rust, scale, and oxides from the metal surface.
4. Water Rinse:
. Chemicals: Freshwater
. Purpose: Rinse off acid residues from the pickling stage.
5. Surface Activation:
. Chemicals: Titanium or zirconium-based activators
. Purpose: Prepare the metal surface for better phosphate coating adhesion.
6. Phosphating:
. Chemicals: Phosphating solution (usually zinc, iron, or manganese phosphates)
. Purpose: Form a protective phosphate layer on the metal surface to enhance paint adhesion and provide corrosion resistance.
7. Passivation / Chromate Treatment:
. Chemicals: Chromate or non-chromate passivation solutions
. Purpose: Further enhance corrosion resistance and prepare the surface for final coating.
Keywords
Water Rinse
Dilute acids
final coating
acid residues
sulfuric acid
Acid Cleaning
pickling stage
metal surfaces
phosphoric acid
proper adhesion
degreasing stage
protective layer
alkaline residues
Alkaline Cleaning
Surface Activation
Chromate Treatment
other contaminants
standard procedure
Alkaline degreasers
subsequent coatings
chemical treatments
Phosphating solution
corrosion resistance
manganese phosphates
typical seven stages
The Seven Tank Process
zirconium-based activators
phosphate coating adhesion
protective phosphate layer
Seven Tank Process Chemicals
chromate passivation solutions
