| Symptom | | Usual Causes | | Correction |
| Dark smudges on work |
| | 1. High pH
2. Low TVC MS
3. Low TVC Catalyst
4. Low chromium concentration
| | 1. Adjust pH
2. Add TVC MS
3. Add TVC Catalyst
4. Add TVC Chromium Compound
|
| White patches on work (non-uniform) |
| | 1. Lead contamination
2. Poor cleaning prior to nickel
3. Part dries prior to chromium plating
| | 1. "Dummy" solution at 15 ASF
2. Improve cleaning
3. Keep parts slightly wet
|
| White deposit at chromium cut-off |
| | 1. Zn, Pb contamination | | 1. "Dummy" at 15 ASF |
| Poor chromium adhesion |
| | 1. Bipolarity during exit from nickel solution
2. Bipolarity during chromium entrance
3. Lead contamination
4. Pre-chromium rinses contaminated with hexavalent chromium
| | 1. Exit nickel solution with some current applied
2. Enter chromium solution with some current applied
3. "Dummy" solution at 15 ASF
4. Dump rinses and remove source(s) of hexavalent chromium
|
| Poor chromium coverage |
| | 1. Low pH
2. Low specific gravity
3. Zn, Pb contamination
4. High air agitation
5. High temperature
| | 1. Correct pH
2. Add TVC Base Compound
3. "Dummy" at 15 ASF
4. Reduce air agitation
5. Reduce temperature
|
| Low chromium thickness |
| | 1. High pH
2. Low agitation
3. Low TVC Catalyst
| | 1. Reduce pH
2. Increase air agitation slightly
3. Add TVC Catalyst
|
| High voltage requirement |
| | 1. Crystallization on anodes
2. Poor electrical connections
| | 1. Dilute solution if specific gravity is high
2. Inspect and tighten loose connections
|
| Crystallization (On tank sides, anodes, piping |
| | 1. Low temperature
2. High specific gravity
| | 1. Adjust temperature
2. Dilute solution
|
| Dark deposits overall |
| | 1. High temperature
2. High pH
3. Metallic contamination
| | 1. Adjust temperature
2. Adjust pH
3. "Dummy" solution at 15 ASF
|
05/14/10
