De-painting with high-speed water jets: Paint removal process and substrate surface roughness

Although the use of water jets for paint removal processes is an accepted procedure, there are just a few studies known which discuss parameter optimization and surface topography in some detail. The paper investigates the effects of water jet kinetic energy and stand-off distance on the mass loss of an organic paint system applied to a steel substrate. It was shown that the material removal process was characterized by a combination of loading intensity and loading frequency. Water drops, formed in the water jet at long stand-off distances, played a notable role. For rather high water jet energies, mass loss exhibited high values at high stand-off distances. For lower water jet energies, however, maximum material loss values appeared at a critical stand-off distance. The transition water jet energy was 600 kJ. It could be shown that the steel substrate topography was not compromised due to secondary surface preparation by water jets. Secondary blast cleaning, however, reduced the profile of the substrate.