FTM 3007 (FED-STD-791 Method 3007) Water Displacement and Water Stability
The ability of a lubricant to protect metals from rust is usually evaluated by coating dry panels with the test sample. But in many real world applications, there is moisture in the system prior to lubrication, such as when a system containing hard to reach crevices needs to be re-lubricated. This test is intended to measure rust inhibition properties in (1) systems where new oil is being applied to areas where moisture is already present (2) systems where the lubricant mixes with water prior to reaching the moist metal to be protected.
Steel panels are sand blasted and cleaned. They are then divided into two groups. The first group is dipped into water, then the test oil. The second group is dipped into water and then the test oil which has been emulsified with water. Both sets are put in a constant humidity chamber for one hour and then visually evaluated. The presence of rust or abnormal surface appearances are reported.