Below are some common issues and solutions when using aqueous cleaners.
The following items are the primary causes for foaming when using aqueous chemistries:
- Wrong concentration (mix is too rich)
- Spray pressure is too high (generally above 60 psi)
- Temperature is too low (defoaming properties are generally activated at temperatures above 110°F
- Buildup of high foaming soils in the bath (certain hydraulic or soy based oils)
- Pump malfunction (pump is sucking air)
For heavy soil applications where oil skimming will be used, skimming is best done when the aqueous bath is 80°F or less. Aqueous cleaners have a tendency to separate at higher temperatures and can have their cleaning surfactants and other additives such as defoamers and rust inhibitors removed from the bath when skimming at temperatures of 160°F or greater thus reducing the effectiveness of the cleaner. It is recommended that oil skimming be performed during an off-shift or over-night to allow the machine to cool down sufficiently.