ASTM D7538-09(2013)

1.1 A newly applied traffic paint film may be exposed to rain of varying intensities shortly after application. Practice D7377 describes a practice for evaluating the water wash-off resistance of traffic paints to a hard rain using a steady stream of water from a faucet at a rate of approximately 5.7 L per min. Practice D7538 is a similar practice that describes the use of an adjustable nozzle atomizing spray device to deliver a spray of water that simulates rain rates from approximately 0.05 to 0.5 L per min. This test can be used to compare conventional and fast-dry traffic paints for their relative ability to withstand rain soon after application on roadway surfaces.