Metal Finishing Guide Book

2013

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Problem Possible Cause How to Correct Poor leveling 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 1. Increase agitation 2. Increase solution temperature to 70°F 3. Increase copper content of solution 4. Add brightener 5. Analyze and adjust chloride Pitting 1. Grease or oil contamination in plating bath 2. Particulate matter in bath 1. Carbon treat bath 2. Filter bath Streaking in deposit 1. Excessive brightener additions 2. Organic contamination 1. "Dummy" solution at 15 ASF. 2. Carbon treat solution Burnt deposit HCD 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 1. Increase agitation 2. Increase solution temperature 3. Increase copper content 4. Increase brightener 5. Analyze and adjust chloride Acid Copper: Panels are usually plated at 2 amps for 10 minutes on brass panels. Problem Possible Cause How to Correct LCD skip plate 1. High brightener 2. High zinc 1. Dummy plate solution 2. Reduce zinc metal Burnt deposit HCD 1. Low zinc metal 2. Low brightener 1. Increase zinc metal concentration 2. Add brightener Appearance After Nitric Post Dip or Clear Chromate Black stain in HCD, overall yellow deposit 1. Iron contamination 1. Reduce iron contamination Black or brown stain in LCD 1. Copper contamination 1. Reduce copper contamination Bright Acid Chloride Zinc: Panels are plated at 3 amps for 5 minutes on steel panels. 480

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