What’s Suddenly Causing a Cleaner’s Short Bath Life?

Q. My cleaner is suddenly experiencing a short bath life. Did something change?

A. The very short answer is, “yes.” However, exactly what those changes could be is a much more nuanced answer than you might expect. They may be changes in the substrate, the oils used in manufacturing, or in some cases a combination of factors that have impacted the entire process line. Given the numerous possibilities, I recommend reviewing all other variables before assuming that the culprit is the cleaning chemistry itself. Doing so will save you time, money and lots of frustration.

With that said, it would seem logical to immediately lay blame on the cleaning chemistry. But hear me out. We can quickly turn rectifiers, heaters and agitation on and off without much work. Flip a couple switches or turn some valves, and boom, you’re in business. However, the moment you decide to pour chemistry into the tanks, the only way to reverse that decision is by making another extremely costly decision: dumping and making a new bath. Therefore, it is always best to start with the basics, and there’s nothing more “basic” than the substrate itself. 

Unfortunately, not all substrates are created equal. Alloys vary wildly. Seemingly small changes can make a big difference in cleaner life as well as the performance of other process chemistries. In fact, your customer or procurement department might change the type and grade of steel being purchased without realizing how or if the change will impact manufacturing. The same goes for brass, zinc or any other material you are plating over. Oftentimes, the substrate is chosen based on end-user requirements with little regard for plating. This can translate to a number of cleaning and plating bath issues. To minimize and quickly adjust to variations in substrate, it’s of utmost importance to engage your customer or purchasing department on a regular basis. Including substrate type and changes as part of a standard process-line audit is also highly recommended.

Another potential perpetrator of your problem involves oils used in manufacturing. Oils are constantly changing—some would say improving. Due to environmental regulations, cost and other factors, synthetic oils are growing in popularity, and there has been a marked reduction in the use of petroleum oils. Like the oil used in our cars, synthetic oils last much longer in an industrial setting than petroleum oils. They also can be much tougher to remove when cleaning the surface of a part. Your best bet is to work with a knowledgeable chemical supplier to establish the right cleaner for the type of oil you will be removing. I like to think of oils as a lock and the cleaner as the key. You have to fit the key to the lock in order to open the door.

As the name implies, water-soluble oils are oils that easily mix into water. However, when cleaning a part, you can never be absolutely certain when the cleaner is spent. The standard practice of splitting the cleaner may not cause the oil to separate. When splitting is not possible, the only option remaining is to dump the cleaner bath when defective plated parts are first identified. Some shops purposely dump the cleaner bath prematurely to eliminate the possibility of jeopardizing part quality. 

Furthermore, parts sitting for a week or more on the shop floor often collect grime, soils and other debris. This contaminant buildup shortens bath life, as the operating solution needs to work harder to clean these parts. Any rust preventatives that have been added to the cleaner operating solution are normally not difficult to remove, but they could also lead to surface contamination.

Additional areas that can lead to shortening cleaner bath life include recycling oil and changes to buffing compounds. Oil recycling systems can introduce non-oil compounds such as hydraulic fluid into to the cleaner operating solution. A little hydraulic fluid can quickly cause a cleaner to fail. Even under ideal circumstances, buffing compound can be extremely difficult to remove. When the compound changes, it can wreak havoc on the cleaning process.

Identifying and addressing deviations in the substrate, oils and the other culprits described here will result in extending cleaner life. Regularly performing an alkalinity test on the cleaner operating solution can provide an additional level of quality assurance and ensure the bath is running at peak efficiency. It’s easy to do; your chemical supplier can arrange for testing.

Today’s cleaners do not last as long as they did in the ‘70s and ‘80s. Why? Most of us are not plating with cyanide baths anymore. Cyanide baths were fantastic for cleaning and plating at the same time; non-cyanide plating baths, while safer to operate and better for the environment, do not have the cleaning power of their predecessors. They do exactly as advertised, which is to “plate.” Modern plating baths are becoming more efficient but less able to plate over contaminates and soil. Therefore, today’s cleaners are taking on a critical role in ensuring optimum performance of the entire plating line and final part quality.