FTM-352 (FED-STD-791 Method 352.1) Effect of Evaporation on Flammability
Spray lubricants, vanishing lubricants and solid film lubricants depend on solvent evaporation after application to function properly. The flammability of these lubricants gives an indication of safe usage ranges. This test may be used to (1) determine the flammability of a lubricant both before and after solvent evaporation or (2) as a screening/specification test for some military specifications, such as those used for hydraulic fluids.
To assess the flammability before solvent evaporation, pipe cleaners are soaked in the sample and then repeatedly drawn over a flame until a self-sustained burn appears. The number of passes is reported. To assess the flammability after solvent evaporation, the sample is placed in a petri dish in a drying oven for the time and temperature ( specified in the method, pipe cleaners are soaked in the remaining sample and then repeatedly drawn over a flame at regular intervals until a self-sustained burn appears. The number of passes it takes for a self-sustained burn to appear is reported.