Abstract: The invention is a method for repairing a protectively coated, locally damaged turbomachinery vane without removing the vane from its parent turbomachinery module. The method includes applying a diffusible coating precursor to the damaged region of the vane and diffusing the coating precursor into the vane in the presence of a nonreactive atmosphere. The nonreactive atmosphere is confined to a chamber that contains the damaged vane, the chamber being bounded in part by the turbomachinery module itself. A conventional stress relief machine is used to heat only the damaged region of the vane to a temperature sufficient to promote diffusion of the precursor into the vane. The method uses equipment and supplies that are routinely available or easily fabricated from common, inexpensive materials. Use of the method avoids the expense and delay of removing the vane from its parent module.