"Are lubricant conditioners a good idea? If so, when should they be used?"
The effective use of special additives or conditioners depends entirely on the application in which they are used. For example, graphite and molybdenum disulfide (often called moly) are referred to as solid lubricants. Graphite is most effective when utilized as an anti‑seize compound, grease additive or in bearing applications in the presence of moisture. Moly is best used as a solid lubricant that is applied by special processes where the lubricant is impregnated into the surfaces of the metal parts.
Some molybdenum compounds are also used as special additives in lubricating oils that are attracted to the metal surfaces as an anti‑wear surface coating. However, when moly is used in this application, it may have limited or no effect if the additive remains suspended, depending on compatibility with the existing oil. Conversely, if these compounds drop out of solution due to incompatibility, the results could be negative, as the compounds can plug oil passages or filters.
Polytetrafluoroethylene (PTFE) or Teflon is a plastic-like solid lubricant that has extremely good lubrication qualities. Like moly, PTFE offers its most effective service as an impregnated coating on certain wear surfaces. It is also used in the manufacture of special bearings that are self-lubricated.
On the other hand, when used as a dispersed additive in oil products, it may not provide any tangible benefit. The theory for its use suspended in oil is that at certain operating temperatures, frictional heating causes the Teflon to melt and adhere to the wear surfaces. However, conflicting evidence exists as to the melting of the Teflon at high sliding speeds.
The other disadvantage of Teflon suspended in oil is that the compound may be removed by the filtration process or drop out of solution and plug oil passages if too much is used. Teflon surface films also tend to lose their attraction for metal surfaces during cooling periods or low temperatures. This is due to the high coefficient of thermal expansion of Teflon.
Some unique lubricant conditioners are available that can improve existing quality oils. These conditioners are produced by blending a compatible base oil with a combination of compatible additives, such as a viscosity-index improver, antioxidant, anti‑wear/extreme-pressure agent, corrosion inhibitor and detergent alkalinity additive.
In cold climates where the poor flow characteristics of many hydraulic oils in temperatures below zero are a problem, a lubricant conditioner can help to overcome this difficulty. This type of conditioner is manufactured by blending an oil with a natural high viscosity index with a pour-point depressant and anti‑wear package that is proven compatible with hydraulic oils. Depending on the concentration used, the conditioner can be mixed with hydraulic oils to improve flow and reduce pump cavitation problems at extremely low temperatures.