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 |
|---|---|---|---|
| Deposit cracks on bend test | Deposit stress high: brightener overdose | Bend test + Hull cell | Hull cell, cut dose per curve |
| Craze lines after chrome | Over-bright deposit meets chrome stress | Timing: before/after chrome | Dose down before chrome audit |
| Powdery, flaky deposit | Metal or pH out of band | Titration + pH | Correct per TDS |
| Brittle only late in bath life | Organics + breakdown products | Turnover count | Carbon trial / plan rebuild |
| Brittle on thin parts only | Over-plating thin sections | Thickness by part class | Split families by weight |
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 bath chemistry is a sensitiser; bend tests flick sharp metal shards. Gloves, shield at the tank, eye protection at the bench.
FAQ
Brittle only on thin parts — why?
They over-plate on the standard cycle: split families by weight and dose each to spec.
How does brightener overdose show up?
First in the Hull cell (bright but stressed band), then as bend-test cracks.
Chrome craze vs nickel brittle — which tank?
Bend the nickel before chrome: if it cracks there, the nickel dose is the cause.