100 g/l to 150 g/l

200 g/l to 225 g/l

250 g/l to 300 g/l

300 g/l to 325 g/l

Final rinsing

Post treatment

Neutralising dip

Heat treatment

High current density

Too high temperature

Presence of grease

Too low current density

Dilute sulphuric acid

Dilute hydrochloric acid

Cadmium cyanide

Sodium cyanide