Ultra-High Pressure Waterjet Removal of Thermal Spray Coatings

Abstract

High-pressure waterjet can be effectively used to remove thermal spray coatings as required during aircraft engine overhaul. The traditionally accepted methods of grit blasting, machining and chemical stripping all have disadvantages that are overcome with waterjet removal. With waterjet, complete removal can be rapidly and economically attained without damage to the substrate. For efficient removal, it is essential to understand the process and to establish an optimal set of operation parameters for each application. This paper presents a few theoretical concepts of jet-coating interaction and results of several experiments to rank the importance of waterjet parameters.

Statistical techniques are utilized to show that pressure, flow and jet traverse velocity are key parameters. As an example of practical application, it is shown that a JT8D burner can can be cleaned in about twenty minutes.