(1) Insufficient chromic acid

(2) Deficient activator

(3) Abnormal pH (too high or too low)

(4) Short passivation time

(1) Supplement chromic acid as needed

(2) Add activator

(3) Adjust solution pH

(4) Prolong passivation time

(1) Insufficient activator

(2) Hazy original zinc coating

(3) Excess zinc ion in bright dip solution

(4) High trivalent chromium level in passivation bath

(1) Replenish activator

(2) Inspect zinc plating quality

(3) Partial replacement of bright dip liquid

(4) Remove cation impurities with cation exchange resin

(1) Rough zinc deposit

(2) Spoiled bright dip bath or insufficient bright dipping time

(3) Shortage of nitric acid

(1) Improve zinc plating process & coating quality

(2) Repair bright dip solution and adjust dipping time

(3) Top up nitric acid

(1) Excessive nitric acid / sulfuric acid

(2) Overlong passivation duration

(3) Excessively high passivation temperature

(4) Insufficient acetic acid

(1) Properly increase chromic anhydride content

(2) Shorten passivation time

(3) Reduce working temperature

(4) Supplement acetic acid