A gas-fired water heater has a combustion chamber with a bottom wall defined by a perforated flame arrestor plate forming a portion of a flow path through which combustion air may be supplied to a burner structure within the combustion chamber. The invention consists of applying a patterned discontinuous layer of liquid resin over at least one side of a layer of reinforcing fibers. This elongated signal electrode is disposed to be electrically isolated from the ground plane. A plurality of second indented sections are located on an outer surface of the transition section. The process is preferably used in applying a coating system to a turbine blade, particularly a stator or a rotor blade of a stationary gas turbine or of an aircraft engine, or to another component in a stationary or aircraft turbine that is subjected to hot gas.