spray torch and the substrate be moved in relation to one another when depositing the tbc this can take the form of moving the torch substrate or both and is analogous to processes used for spray painting this motion combined with the fact that a given plasma spray torch sprays a pattern which covers a finite area e g has a torch footprint results in the tbc being deposited in layers in one exemplary embodiment the process consists of eight 8 spray passes with the torch or nozzle located a distance of about 4 5 inches from the component to be coated using a computer controlled program with robotic motion for reproducibility this process produces a uniformly hard dense ceramic coating adding about 0 002 u2033 per pass for a total thickness of approximately 0 016 u2033 this allows for about 0 002 u2033 to be abraded during the surface finishing operation that is required to achieve the required surface roughness and thickness specifications the invention here is a modification to this otherwise known process specifically this invention adds one additional pass of the plasma spray torch using the same parameters and motions as in all of the prior passes except that the last pass is made from a distance of about 11 0 u2033 more than 2 u00d7 the distance for the first 8 passes this added distance creates an outer u201c sacrificial u201d layer that is less dense i e more porous the additional porosity is what makes this.