There are a few things that will affect the life of your cleaner baths. The first is the condition of parts that you are putting into the bath. If they are covered in and dripping with oil/grime, your cleaner isn’t going to last very long as it will have a lot to clean up. This is easily fixed by lowering the amount of oil used to ship or manufacture the parts. Note that this may not be possible if you aren’t in charge of manufacturing the parts. It’s recommended that you discuss this with those who send you the parts to be plated. Additionally, depending on the type of cleaner you are using, adding a weir to your cleaner tank may help lengthen bath life by removing oil from the top of the bath.
The second thing that greatly affects cleaner bath life is the quality of the water that you are using to make up the bath. There are three broad categories of water, and each has different properties that may affect the bath life. The types of water are hard, soft, and purified. Examples of hard water include well water, pond/lake water, and river water. Hard water is the worst for bath life, as it contains lots of dissolved minerals. These minerals can prevent the cleaner from pulling the oils and grime into the solution and off the surface of the part. The easiest way to think about it is that there can only be so much “stuff” in solution at one time. Soft water is just hard water that has had many of the minerals removed from it. This can be accomplished in several ways and is likely a conversation for a different time. Since soft water has fewer dissolved minerals than hard water, cleaner baths made with soft water tend to last longer when compared with hard water baths.
Purified water is just what it sounds like, soft or hard water that has been purified. Like soft water, there are several different ways to make purified water, all of which are out of the scope of this answer. Baths with purified water will last the longest, due to the fact that nearly all or all of the dissolved minerals have been removed. This leaves just pure, clean water.
The final element that will affect the life of a cleaner bath is the type of cleaner used. This is very much a case-by-case thing. There are many, many types of oils and compounds used to manufacture parts, and for every oil and buffing compound, there is a surfactant/soap that will clean it. For instance, paraffinic oils can be very difficult to clean. However, there are definitely cleaners that are designed to remove paraffinic oils from the surface of the part. The best thing I can recommend for this is to talk with the oil supplier and cleaner supplier to find the best solution. Along the same vein, check to see what temperature the cleaner should run at. Oftentimes, cleaners will have a range that they can be run at. It is important to make sure the cleaner is in that range to get the best cleaning. While it may not affect bath life directly, it can improve the cleanliness of the parts.
Short cleaner bath life can be a frustrating problem, especially if you feel that you aren’t getting your money’s worth out of the bath. Hopefully one of the three things mentioned here will help you extend that bath life and get more out of the baths. Regardless, one thing worth keeping in mind is that your cleaner is the first line of defense for your plating line. It is designed to be used up and trashed, so that your plating solution isn’t chewed up by the surface contaminates. The best thing you can do is talk to whoever supplies your cleaning chemistry if you are struggling with bath life. They will be able to help you target your efforts to lengthen bath life.