A method for fabricating pipeline coating samples containing synthetic disbonds to be used in estimating a condition of a coating of an underground pipeline. The method includes the steps of providing a section of a pipe having a predetermined diameter and length; installing end caps on opposing ends of the pipe section, each end cap having an electrical connection extending therefrom; applying a material having a low dielectric coefficient around the pipe segment between the end caps to simulate an air-filled disbond; varying the coverage area of material to simulate various disbond sizes; and wrapping the pipe segment and end caps with tape to cover the material having a low dielectric coefficient.