Scope of this guide
Senior version: the fix set with parameter windows, boundary cases and the discipline that keeps them fixed.
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 |
|---|---|---|---|
| Rough, gritty deposits | Bag burst: sludge bleeding | Bag inspection under load | Replace bag, polish filter |
| Anode current falls | Bags clogged / anodes passivated | Voltage vs amps trend | Clean or re-bag anodes |
| Nickel content drifts down | Anodes not dissolving | Daily metal titration | Check bag choke and anode area |
| Particles despite filter | Sludge already in bath | Filter ΔP + housing check | Full filter service; settle, syphon |
| Recurring after refill | Bad bag media or wrong size | Bag spec audit | Standardize bag spec per tank |
The fix set
- Fix 1 — bag spec — Right weave per bath (nickel: tight PP); no improvised cloth
- Fix 2 — inspection rhythm — Weekly visual under load; sludge at the seam = change now
- Fix 3 — anode inventory — Keep stub anodes from jamming baskets; weight in/out logged
- Fix 4 — filter teamwork — Bag failure floods the filter: service both, log ΔP daily
- Fix 5 — replacement ledger — Bags dated at install; replace on schedule, not on failure
Case method
A nickel line chased rough deposits for weeks with filter changes. The anode bags were three years old and split at seams under load; sludge rained every time current pulsed. A dated bag ledger and weekly under-load visual ended the family. (Method illustration: your own bag-age records will show the same curve.)
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: anode work means live bus bars and hot, chemical-soaked bags. Lock-out before touching baskets, drain and rinse bags outside the tank, gloves and shield throughout.
FAQ
How do I standardize bags across lines?
One spec per bath type, dated ledger, supplier approved; audit quarterly.
Clean or replace after a burst?
Replace the bag, settle and syphon sludge, polish filter, then Hull cell before production.
Anode inventory discipline — what does it prevent?
Jammed baskets and weight drift; weight in/out log catches both.