How Water Affects Additives
From "Fluid Contamination Control":
Water in tribological fluids (other than water-based fluids) leads to a multitude of problems in terms of system damage and failure. Perhaps the worst threat of water contamination in storage is its reaction with additives and the damaging reaction products.
Moisture causes a filter-clogging slime to form in fluids containing tricresyl phosphate (TCP), an antiwear additive used in tribological fluids where an alkali is present. If ZDDP (zinc dialkyl dithiophosphate) is used as the antiwear additive instead of TCP, many deteriorating mechanisms could exist; suffice to state here that ZDDP can decompose to form hydrogen sulfide and, in the presence of moisture, transform into a highly corrosive acid (sulfuric acid). Even in fluids of the corrosion-prevention type, moisture causes an egg-white type slime. According to T.N. Dean, when moisture is present, corrosion-preventive additives can exhaust themselves by "wrapping up" the moisture in additive and water dispersion.
From "Fluid Contamination Control":
Water in tribological fluids (other than water-based fluids) leads to a multitude of problems in terms of system damage and failure. Perhaps the worst threat of water contamination in storage is its reaction with additives and the damaging reaction products.
Moisture causes a filter-clogging slime to form in fluids containing tricresyl phosphate (TCP), an antiwear additive used in tribological fluids where an alkali is present. If ZDDP (zinc dialkyl dithiophosphate) is used as the antiwear additive instead of TCP, many deteriorating mechanisms could exist; suffice to state here that ZDDP can decompose to form hydrogen sulfide and, in the presence of moisture, transform into a highly corrosive acid (sulfuric acid). Even in fluids of the corrosion-prevention type, moisture causes an egg-white type slime. According to T.N. Dean, when moisture is present, corrosion-preventive additives can exhaust themselves by "wrapping up" the moisture in additive and water dispersion.
