Scope of this guide
Management version: this defect as cost and risk — the metrics, audit points and claim defence.
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 |
|---|---|---|---|
| Dull/gray only on edges & points | CD above bright range | Position map vs amps | Cut amps in steps; map again |
| Dull everywhere, worse at high CD | Brightener exhausted or overdosed | Hull cell panel | Hull cell before dosing |
| Dull after bath cools | Temperature below window | Temp log overlay | Hold 50–60 °C Watts band |
| Dull + rough together | Solids on top of CD stress | Filter ΔP + bag check | Filtration first, then amps |
| Dull band follows rack family | Old rack contacts hogging current | By-rack amp compare | Retire/rebuild those racks |
Cost, metrics and defence
| Cost line | Driver | Metric | Lever |
|---|---|---|---|
| Replate hours | Dull escapes to chrome | FPY by defect family | CD mapping at load-in |
| Brightener spend | Dosing by feel | L per Amp-hour trend | Hull cell routine |
| Energy | Cold-bath compensation | kWh vs temp variance | Heat interlock |
| Claims | Dull under chrome | PPM by customer | Nickel gate before chrome |
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 salts are skin sensitisers; hot acid solutions splash. Face shield at tank, nitrile gloves, eyewash in reach.
FAQ
What does a dull nickel day cost?
Chrome stoppage plus replate: the nickel gate is cheaper than the chrome queue.
Which trend predicts dull weeks?
Brightener L per Amp-hour and pH log completeness; both drift first.
Rack rebuild schedule — business case?
Contact age correlates with dull rate; scheduled rebuilds beat replate hours.