Understanding Nickel Plated Hull Cell Panels: A Comprehensive Guide

 This blog post provides a detailed overview of evaluating nickel plating baths using Hull cell panels, including preparation, analysis, and common issues such as burning, poor leveling, and roughness.

Nickel plating is a crucial process in metal finishing, and evaluating the quality of nickel plating baths is essential for achieving optimal results. This guide will walk you through the process of using Hull cell panels to assess nickel plating baths, including preparation, analysis, and troubleshooting common issues.

Preparing Hull Cell Panels for Evaluation

When evaluating nickel plating baths, it is important to use either brass Hull cell panels or standard zinc-coated steel Hull cell panels. Here are the steps to prepare the brass panels:

1. Remove Protective Film: Brass panels are usually protected with a plastic film that must be removed before evaluation.
2. Clean the Panel: Use a brass cleaner solution and apply direct current with a short reverse to clean the panel thoroughly.
3. Rinse and Acid Dip: After cleaning, rinse the panel and dip it in a solution of 5% sulfuric acid to ensure it is properly prepared for Hull cell evaluation.

Understanding the Reference Hull Cell Panel

The reference Hull cell panel is crucial as it demonstrates the characteristics of the nickel plating bath when operating at its full potential under stable conditions. All Hull cell panels used in this analysis are 2 Amp, 10-minute panels. It is important to consult your supplier for specific instructions, as different types of plating baths may require different conditions.

Characteristics of a Reference Panel

A well-functioning reference panel will exhibit:

• Full brightness across the range of current densities
• No burning or cloudiness
• A smooth deposit without roughness or impurities

Conducting the Hull Cell Analysis

To begin the analysis, follow these steps:

1. Sample the Nickel Plating Bath: Take a sample of the nickel plating bath to evaluate the quality of the work coming off the line.
2. Run a Nickel Hull Panel: Use the sample to run a nickel Hull panel at the correct amperage and time, ensuring the temperature is similar to that of the operating plating bath.
3. Evaluate the Panel: After completion, the panel does not require further processing, unlike other plating solutions.

Common Issues in Nickel Plating Baths

During the evaluation, you may encounter several common issues, each with specific causes:

1. Burning

Burning is indicated by an extremely dull gray area on the panel. The principal causes include:

• Low operating temperature
• Low plating salt concentrations
• High pH levels

2. Poor Leveling

Poor leveling is characterized by a cloudy, dull area on the panel. Causes include:

• Imbalance of addition agents
• Low pH
• High pH
• Improper temperature

3. Roughness

Roughness can be felt by running a coin over the panel, even if it is not easily visible. Causes of roughness include:

• Impurities in the bath, such as hard water salts
• Imbalance of plating salts
• High pH

Conclusion

Evaluating nickel plating baths using Hull cell panels is a vital process for ensuring quality in metal finishing. By following the preparation and analysis steps outlined in this guide, you can identify and troubleshoot common issues effectively. For further assistance, consider obtaining a copy of the Asterion troubleshooting guide for nickel plating or arranging a technical consultation.

This guide is intended to provide general guidance and is not a substitute for the recommendations of a trained metal finishing professional. Always exercise caution and consult with experts before making changes to your plating bath solutions.