Wet-blasting machines type PP-UM are designed to manage an homogeneuos mixture of shot, air and water. The final result is a soft blasting process on the surface (in comparison to a dry blasting process). The common mixture ratio is 30% shots and 70% water. The most common shots are corundum, silicates and glass beads. A special pump (heavy duty design for aggressive liquids) permits to maintain homogeneously the solution and delivers the mixture to the blasting gun. The compressed air guarantee the correct shot impact on the surface (6-8 bars). The process is manual.