Abstract: A method of refurbishing a transition duct (100) for a gas turbine system includes providing the transition duct. The transition duct has a first wall (221) defining a first passageway (110) and having holes (223) through a metal layer (322) and a ceramic layer (323), and the transition duct also has a second wall (222) adjacent to and separate from the first wall and external to the first passageway, where the first and second walls define a second passageway (210) coupled to the first passageway through the holes in the first wall. The method further includes masking the holes in the first wall, sealing the first passageway, and after sealing the first passageway, using a liquid etchant to chemically remove the ceramic layer from the first wall while keeping the liquid etchant out of the second passageways.