Troubleshooting a Non-Cyanide Alkaline Zinc Bath
Are there rules of thumb for troubleshooting a non-cyanide alkaline zinc bath?
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Q. Do you have a troubleshooting chart for non-alkaline zinc plating baths? –S.S.
A. The chart below covers some of the more common problems that you may encounter with a non-cyanide zinc plating bath. Keep in mind that the vendor of the chemicals used in your bath is your best source for this type of information.
|
Problem |
Possible Causes |
Possible Solutions |
|
Blisters |
Brightener too high |
Carbon treat or zinc dust |
|
|
Inadequate cleaning |
Better cleaning cycle |
|
Bath chemistry off |
Analyze and correct |
|
|
Organic impurities |
Carbon treat |
|
|
Chromium contamination |
Dummy or sodium hydrosulfite |
|
|
Metallic contamination |
Zinc dust treat |
|
|
Burned/dull high CD areas |
Brightener low |
Hull cell and adjust brightener concentration |
|
|
Temperature low |
Adjust temperature |
|
Metal content low |
Raise metal content |
|
|
High CD |
Lower CD to specified range |
|
|
Dull low CD areas |
Brightener low |
Hull cell and adjust brightener concentration |
|
|
Bath temperature too high |
Cool plating bath |
|
Sodium hydroxide concentration low |
Add to a minimum of 60 g/L |
|
|
Organic contamination |
Carbon treat |
|
|
Cloudy deposit |
Brightener low |
Hull cell and adjust brightener concentration |
|
|
Metal content high |
Analyze and dilute bath |
|
Iron contamination |
Dummy bath |
|
|
Zinc concentration drops rapidly |
Anode area low |
Increase anode area |
|
|
Sodium hydroxide concentration low |
Analyze and add as needed |
|
Anodes polarized |
Increase anode area |
|
|
Zinc continually increases |
Anode area high |
Reduce anode area |
|
Rough deposit |
Suspended particles in bath |
Check filtration system |
|
Excessive brightener consumption |
Metal content high |
Analyze and reduce |
|
|
Bath temperature high |
Reduce bath temperature |
|
Organic contamination |
Carbon treat |
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