Metal Finishing Guide Book

2011-2012 Surface Finishing Guidebook

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Problem Poor leveling Possible Cause 1. Insufficient agitation 2. Solution temperature is less than 70°F 3. Copper content of solution is too low 4. Brightener concentration is too low 5. Chloride content is out of normal range Pitting Streaking in deposit Burnt deposit HCD 1. Grease or oil contamination in plating bath 2. Particulate matter in bath 1. Excessive brightener additions 2. Organic contamination 1. Insufficient agitation 2. Solution temperature is less than 70°F 3. Copper content of solution is too low 4. Brightener concentration too low 5. Chloride content is out of normal range Acid Copper: Panels are usually plated at 2 amps for 10 minutes on brass panels. Problem LCD skip plate Burnt deposit HCD Possible Cause 1. High brightener 2. High zinc 1. Low zinc metal 2. Low brightener How to Correct 1. Dummy plate solution 2. Reduce zinc metal 1. Increase zinc metal concentration 2. Add brightener Black stain in HCD, overall yellow deposit Appearance After Nitric Post Dip or Clear Chromate 1. Iron contamination Black or brown stain in LCD 1. Copper contamination 1. Reduce iron contamination 1. Reduce copper contamination Bright Acid Chloride Zinc: Panels are plated at 3 amps for 5 minutes on steel panels. 1. "Dummy" solution at 15 ASF. 2. Carbon treat solution 1. Increase agitation 2. Increase solution temperature 3. Increase copper content 4. Increase brightener 5. Analyze and adjust chloride How to Correct 1. Increase agitation 2. Increase solution temperature to 70°F 3. Increase copper content of solution 4. Add brightener 5. Analyze and adjust chloride 1. Carbon treat bath 2. Filter bath 470

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