Scope of this guide
Junior version: what you will see, what you record, and what you never touch. Recognise early, escalate fast.
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 |
|---|---|---|---|
| Burnt, gray nodules on edges/high points | Local CD far above window | Position map vs rack layout | Cut total amps; add thieves |
| Bare spots in recesses while edges burn | Throwing power ceiling | Coverage vs position chart | Aux anode trial on recess |
| Burns after bath cools overnight | Temperature-CD coupling | Temp + amps log overlay | Interlock heat to line start |
| Burns only on new racks | Contact resistance low, current hogging | Contact check by rack age | Balance load across racks |
| Coverage loss with normal burn | Catalyst ratio drift | Hull cell + titration | Correct sulfate ratio 100:1 |
Recognise, record, escalate
| You see | You do | You never do |
|---|---|---|
| Burnt edges | Photograph, note rack row, report | File or polish burns off yourself |
| Bare recess | Mark position on rack sketch | Turn amps up to 'push' coverage |
| Burns on one rack only | Flag that rack for contact check | Swap racks silently |
| Any sudden pattern change | Stop, report with last good first article | Run the shift on hope |
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: chromic acid mist is a carcinogen and burns skin. Exhaust running before load-in, face shield, and immediate first aid for any chrome burn.
FAQ
Why do edges burn first?
Current crowds onto points and edges — that is where CD is highest. Geometry fixes it, not more chemistry.
What do I record for a burn?
Rack row, position, photo, tank temp. The pattern points at the fix.
Can I just lower the amps myself?
Report first: the setting may be protecting recess coverage. One change at a time by the senior.