Pure water for cleaning liquid, after the activation of the workpiece by the flow of water into pure water cleaning. Ultrasonic cleaning (1 ~ 4 Min), thoroughly remove harmful particles and dilute zinc casting shrinkage and the solution reached the pre plating process (the last procedure). The best effect to prevent blisters on the coating, hemp sand.
The pre infusion is (2~8)%NaCN solution, which neutralizes the acid solution and purify the activated surface. Pre soaked workpiece without cleaning can be directly pre plating, can effectively prevent the workpiece one slot, impurity pollution caused by through replacement reaction before power coating is rough, foaming, and reduce the pre plating bath, to improve the quality of pre coating.