Alkaline Zinc Troubleshooting: Identify and Resolve Issues

Alkaline zinc plating is a widely used electroplating process known for its excellent corrosion resistance and uniform coverage. However, like any industrial process, challenges can arise that require careful troubleshooting to maintain optimal performance.

In this blog post, we will explore how to identify and resolve common plating issues, ensuring your operations run smoothly and efficiently.

Identifying Plating Problems

The first step in troubleshooting alkaline zinc plating issues is identifying the issues. Common visual indicators include dull or cloudy deposits, blisters, rough areas, and uneven coverage. These issues can significantly affect the quality and appearance of the plated parts, leading to potential rework or rejection.

Visual Inspection

Conducting a thorough visual inspection of the plated parts is crucial. Look for signs of dullness, cloudiness, blisters, or uneven surfaces. Pay close attention to high current density areas for burning or dullness and low current density areas for dull deposits. These defects may indicate underlying issues such as improper bath chemistry or contamination.

Hull Cell Panels

Running Hull cells is another effective method for diagnosing plating issues. These tests help evaluate plating thickness and appearance at different current densities, providing insights into the bath's performance.

Common Issues and Pavco's Solutions

Once you've identified the issues, the next step is to address the root causes. Here are some common issues encountered in alkaline zinc plating and their corresponding solutions, powered by Pavco's expertise:

Slow Plating Speed / Poor Coverage

Check the zinc metal and starter concentrations and verify they are within the recommended range. Ensure the caustic soda level is at least 16 ounces per gallon.

High levels of carbonates in the alkaline zinc plating bath can significantly reduce the plating speed. Carbonates form as a byproduct of the chemical reactions in the plating process, accumulating over time. As carbonate levels increase, they interfere with the efficiency of the plating bath, which can lead to slower deposition rates,uneven coverage, and in some cases a burn like pattern in the HCD

Blisters or Rough Deposits

Blisters and rough deposits are often caused by excess brightener or insufficient cleaning. Reduce the brightener concentration if necessary and improve the cleaning cycle.

High-performance cleaners and filtration solutions help eliminate contaminants, ensuring a smoother finish and better-quality plating.

Dull or Burned Deposits

Adjust the starter and brightener levels based on Hull cell test results and check the plating bath temperature. Verify that the current density is within the proper range and maintain the balance of NaOH to ZnO, preventing uneven deposits and ensuring high-quality results.

Excessive Brightener Consumption

Excessive brightener use can lead to higher costs and inconsistent plating results.. Skip plating can also occur in the LCD when brightener concentration is too high in the plating bath. A carbon treatment will remove excess brightener from the plating bath.

Uneven Distribution

Uneven distribution of alkaline zinc plating can result from high or low zinc and or starter concentrations. Poor anode placement and a lack of solution agitation can also cause poor distribution.Effective troubleshooting of alkaline zinc plating issues requires a proactive approach and attention to detail. By identifying issues early and implementing routine analysis and hull cells, you can maintain high-quality plating results while reducing operational costs.

Pavco's plating chemistries and expert support can help you overcome challenges and optimize your plating processes. Contact us today to learn more about how our innovative solutions can elevate your plating operations.