Methods to remove an EBC from a substrate and to repair a coated component

A method for removing an environmental barrier coating from a coated component that includes a silicon-containing substrate, a bondcoat on the silicon-containing substrate and comprising a silicon-containing material, an environmental barrier coating on the bondcoat, and a thermally grown oxide layer positioned between the bondcoat and the environmental barrier coating, the method comprising:

• contacting the coated component with an etchant liquid comprising 5% by volume to 70% by volume of hydrogen fluoride and a solvent, wherein the hydrogen fluoride reacts with silicon oxide in the thermally grown oxide layer to thereby remove the thermally grown oxide layer and the environmental barrier coating from the bondcoat.