Troubleshooting Process Line

It would be wonderful if everything worked smoothly all the time. But there will be times when things don’t work exactly as planned. That is when a good troubleshooting process will help you identify the issue quickly and develop a comprehensive resolution plan.

When troubleshooting a process line start with the following steps:

1.    Completely determine all of the symptoms of the problem

2.    Review when the problem started.

3.    Production records which include all the tank analysis, temperature and additions.

4.    Compare all the analysis, temperature and additional parameters to the standard range.

5.    Look for trends in one or several parameters, take note of any differences.

The next part of the process is to look at the defect itself. Sometimes the defect can be seen by the naked easily with a cause ie. finger print visible, water break lines etc.

In other cases  using some type of magnification is helpful in determining what happened. The quickest type of magnification is a 10X-20X loop. This handheld loop is non destructive, leaving the part intact after examination.

The next step up the ladder is a table top unit that can magnify up to 1000X. The last level of magnification is SEM scanning electron microscope with ranges of magnification 50,000X plus. These last two levels of magnification require part modification to look at the parts. The parts must be cut or bent to be used on the machine. The table top and SEM techniques require the part be destroyed to look at effectively. If the part cannot be destroyed the only option for observation is the 10x-20x loop.

What to look for

Using whatever form of magnification  works often times the defect is plain as day and the possible cause is revealed. The defect might be a sliver connected to the base metal after improper buffing. It could also be in the metal itself, porosity in the casting, inclusion in the base metal or simple mechanical damage (part has a ding) to the base metal. Even hazes can be caused by microscopic base metal defects. Also, the brighter the deposited metal the easier it is to see defects on the part.

Defect location

Your next job is to determine where the defect is in the base metal or the plated deposit. Oftentimes no clear cut distinction is possible, or the defect is actually a combination of the base metal and the plated metal.

The final step in the process is the gather the evidence and review what might be causing the issue. Changes in chemistry, or trends in chemistry, of the plating bath or the cleaners can be directly related to the defect if it is coming from the deposited metal or on the surface of the part.

Defects in the base metal can be traced to the handling, polishing or casting process. Some parts are defective before being plated and the plating process brings them to the surface. With all of these possibilities it truly is an art to effectively troubleshoot any plating process.