in the compartment so that an inboard portion 70 extends over the bore 28 along an outboard portion 72 the first face 66 may contact the shoulder surface 34 the surface 64 may be in close facing or contacting relationship to the surface 42 along the inboard portion 44 of the counterbore the mask may be retained in engagement with the substrate exemplary engagement is by non adhesive mechanical means exemplary mechanical means include a clamp 400 engaging the inboard portion 70 and biasing the mask in the direction 502 the exemplary clamp 400 may be a portion of a fixture supporting the substrate during coating application and or additional steps with the mask engaged the coating 80 may be built up e g by hvof spray exemplary coatings are carbide based e g consisting in majority weight part of one or more of wc crc and nicrc nicrco mcraly nial or other nickel alloy coatings exemplary hvof spray apparatus and methods may involve substrate temperatures of 300 500 u00b0 f the as sprayed coating 80 has a first portion 82 principally along the surface 42 and a bridging portion 84 protruding radially inward along the mask second face 68 the as applied coating has a compartment facing surface 86 and a surface 88 along the mask after coating.