When to Increase Spray Rinsing in Acid Zinc Plating

Spray rinsing is critical for efficient water use and plating quality.

Author: Marisa

Spray rinsing is critical for efficient water use and plating quality. Increase spray rinsing in the following situations:

1. High-Throughput Production

• When: Running continuous or high-speed plating lines.

• Why: Prevents drag-out contamination and ensures thorough cleaning.

2. Thick Zinc Deposits (≥15 μm)

• When: Plating heavy coatings (e.g., automotive parts).

• Why: More drag-out of plating chemicals requires stronger rinsing.

3. Sticky or Viscous Solutions

• When: Using brighteners/additives that increase drag-out.

• Why: Reduces chemical carryover to subsequent tanks.

4. Post-Plating Passivation

• When: After chromate/trivalent conversion coating.

• Why: Prevents staining and uneven passivation layers.

5. Defects Observed (Dull Spots, Water Stains)

• When: Poor rinsing causes residue on parts.

• Why: Ensures complete removal of acidic/chemical traces.

6. Water Conservation Needs

• When: Reducing wastewater volume.

• Why: Spray rinsing uses less water than immersion rinsing.

Best Practices:

• Adjust spray pressure (1–3 bar) for optimal cleaning without splashing.

• Use multiple spray stages for critical processes (e.g., before and after passivation).

• Monitor TDS (Total Dissolved Solids) to determine rinsing efficiency.