Scope of this guide
Intermediate version: symptom-to-cause triage with the confirm-by column — find the variable, run one change, verify.
Series: finishing.com recurring questions answered with platingclub line practice. Parameters are industry-standard starting ranges — confirm against your supplier TDS.
Triage: symptom → confirm → first move
| Symptom | Likely root | Confirm by | First move |
|---|---|---|---|
| Uniform haze all over | Metallic contamination (Cu, Zn) | Hull cell: dull low-CD band | Dummy plate at low CD |
| Cloudy streaks that follow rack | Wetter shortage / surface tension | Stalgmometer reading | Titrate to 35–45 dyn/cm |
| Cloud with pinprick pits | Organics + gas | Hull cell banding | Carbon trial before dosing |
| Haze on castings only | Base metal drag-in (Zn) | By-alloy pattern | Segregate alloys; check strike |
| Haze after maintenance day | Work done: filter change, make-up | Revert one change | Restore and re-verify |
Engineer notes
- One variable per corrective action; verify with the confirm-by column.
- Records beat memory: log every trial on the tank card.
- Two failed actions in a row is a senior call — escalate with your log.
Safety: nickel baths are skin sensitisers and dummy plating runs live tanks unattended overnight — check flood, ventilation and lock-out before leaving.
FAQ
Hull cell shows dull band at low CD — meaning?
Metallic contamination: copper or zinc dummy out at low CD overnight, then re-test.
Wetter or brightener first for streaks?
Measure surface tension first: streaks that follow rack position are wetting, not brightener.
Why do castings haze more?
Zinc drag-in on shared racks; segregate fixtures and watch the strike.