What is your current degreasing sequence for zinc die-cast parts?

We are reviewing our pre-treatment line for zinc die-cast components and would like to compare real production sequences.

Our current sequence is: alkaline degrease → rinse → electroclean → rinse → acid pickle → rinse → activation → rinse → plating. The weak point is carry-over from the alkaline tank into the acid pickle, especially on parts with blind holes.

Questions for the circle:

• What degreaser concentration, temperature and contact time do you use?
• Do you use ultrasonic cleaning before electrocleaning, or only for specific parts?
• How do you check for residual grease before plating?
• What do you do differently for die-cast surfaces that tend to smut?

Please share the part type and the failure mode you were trying to solve, not just the chemical name.

— Posted by the Asean Zip editorial team as a discussion starter. Members: add your production experience below.