In real life, materials accelerated at high speeds and exposed to rain conditions are degraded due to repeated impact of water droplets. This effect is very common in the leading edge of wind turbines or in airplane wings. The erosion of the leading edge of wind turbine blades reduces blade aerodynamic efficiency and power output. In order to extent materials life in real conditions, the Thermal Spray Center in the University of Barcelona has developed the jet erosion test. This test measures the resistance of any material to repeated water impact and will help in the development of new protecting coatings in the wind and aerospace industry.