Water

Water is one of the most common components in modern coolants because of its high heat capacity, low cost and general availability. Typically, more than 90% of the liquid in a coolant is water in the case of no freeze protection, and more than 50% is water when freeze protection of −40°C is required. Considering the large amount of water present in a coolant, attention to the quality of the water used to produce and dilute coolants is more than warranted.

The main parameters used to determine the quality of water necessary for a coolant are the pH, the amount of insolubles present, the concentration of corrosive ions such as chloride and sulfate, and the water’s total hardness. An extremely high or low pH in the water can offset the pH of the coolant’s dilution. Chloride and sulfates are ions that increase a coolant’s corrosivity of metals, and insoluble material can cause increased erosive wear and water pump seal damage. Hard water ions (calcium and magnesium) can precipitate with some additives, but can also appear as hard carbonate scale (so-called boiler stone). This can be the case with some phosphate containing coolants if not properly designed.

While our extended-life organic additive technology is compatible with hard water, we do not recommend the use of hard water, softened water that has been conditioned with salt, and sea water. Distilled water or deionized water is recommended to add to glycol or to water based coolants in engine cooling systems.

If distilled water or deionized water is not available, use water that meets or exceeds the minimum acceptable water requirements listed below to minimize scale deposits:

If water quality is questionable or uncertain, it is recommended that commercial ready-to use dilutions are used, since all major coolant producers will market those using de-ionized or distilled water.