RESOURCES.

Consult with one of our fluid specialists or the Technical Data Sheet (TDS) for the target ratio or concentration of coolant for the specific operation. The best method for mixing coolant and water is to use the “O.I.L.” method – “Oil in Last.” Always mix by adding the concentrate into the water.

For example, if the target concentration is 6.7% or a 1:15 ratio, add 15 parts of water to your container, then add 1-part coolant to the mixture.  Be sure the fluid is properly mixed. 

To assure the correct dilution, use a refractometer to get a reading from the mixed solution. The target refractometer reading can be found on the Technical Data Sheet (TDS). If your reading is higher than suggested on the TDS, then you have too much coolant concentrate in your mixture. Conversely, if your reading is lower, then you have too much water.

A “clean and dump” is strongly recommended before using a new coolant over an existing coolant. Dumping a new product over an existing product can only be done when going from a synthetic to synthetic, semi-synthetic to semi-synthetic, or soluble oil to soluble oil.

Most often, cleaners and degreasers contain chemicals that weaken the emulsion stability of water-soluble coolants. When the emulsifier is compromised, the oil will split from the water. At this point, the coolant must be removed, and the sump must be recharged.

The best lubricant always depends on the process, the type of metal being formed, the application method of the lubricant (recirculating flood, roller coater, spray, etc.), the part finish and the desired tool life. For optimal results, consult with one of our fluid specialists.

With proper storage (indoors in a regular plant environment/temperature), most coolants can last up to 1-2 years. However, any coolant over a year old should be evaluated by a fluid specialist.

Foaming may be the result of soft water, high-pressure machining, or soaps/contaminants within the system.

In soluble oils, mix instability may be the result of an invert emulsion formation caused when the operator adds water to the coolant, rather than following the correct procedure of adding coolant to the water.

The rancid, “rotten egg” smell is usually due to bacteria growth in the coolant. A “locker room” or “foot” odor is an indication of fungus or yeast growth. Besides the unpleasant smell, excessive bacteria/fungus in a coolant can cause skin issues or dermatitis to the operator. It also can lead to poor tool life and corrosion on the machined metal as well as the machine. Maintaining proper coolant mix ratios, controlling the pH, and removing tramp oil will prolong coolant life.

Most cases of dermatitis are due to an elevated coolant concentration. This heightened concentration of coolant means a higher alkalinity level, which causes the skin the fluid comes in contact with to be irritated. Another cause of dermatitis can also be from the presence of bacteria in the sump. Practicing good maintenance can help prevent these abnormal coolant situations from occurring, thereby lowering the chance of dermatitis.

The coolant may lack the necessary metal deactivators that ensure a compatible machining environment for aluminum and other metals. A high percentage of tramp oil could be contributing to metal staining; therefore, sludge should be removed on a regular basis from sumps.   Another possible contributing factor may be from galvanic reactions occurring between the machining of dissimilar metals.

Machine rust can be caused by many different factors:

• Concentration: The concentration of the metal working fluid (MWF) to water may be too low. Consult our fluid specialists or the Technical Data Sheet on our website to confirm the correct percentage or refractive index.
• Premix: Avoid adding straight water to the sump. Instead, have a premix on water and coolant on hand. 
• Contaminants: Has the metal working fluid been in contact with any contaminants? Contaminants include cleaners, solvent, rust removers, or oil.
• Age: The age of the metal working fluid in the sump can contribute to corrosion.
• Tramp oil: Oil contamination from slides ways, hydraulic oil, or metal protectant oil that is present in the sump. Tramp oil can cause depletion of corrosion inhibitors in the metal working fluid. 
• Water Hardness: The hardness of your water may be affecting the corrosion inhibitors in the metal working fluid.