The inner sections of a gas turbine are exposed to combustion gases and experience high temperatures as well as accelerated corrosion reactions. To protect parts from these extreme operating conditions, a ceramic thermal barrier coating of TBC is applied by plasma spray. This process consists of projecting molten particles at very high temperature on the substrate, on which it solidifies upon contact. To apply the ceramic accurately and to avoid clogging of small cooling hole, a mask is used during the plasma coating. This mask is mainly achieved in the industry by manual application of a protective tape. The required accuracy and the wide variety of geometries to cover make masking a very complex and difficult task to automate. This memoir introduces an alternative to manual masking by mean of automated application of plasma spray resistant polymers. The endurance of the new product and its compliance with the industry standards have been validated by a series of experiments on representative parts. A geometric model of deposition is used to predict surface coverage according to the different application parameters. Several strategies for robot motion planning were evaluated on flat surfaces and rotating parts. On the basis of the geometric model, trajectory optimization methods are proposed to maintain a constant thickness and edge definition. Finally, the results show that it is possible to automate the masking operations on turbine components and open the door to many improvements in both quality and performance for the plasma spray coating method in the aerospace industry.