A method of manufacture comprising: forming a first metallized tie layer on a first surface of a non-metallic spacer component , the non-metallic spacer component configured to join a first component and a second component ; and being characterised by the following steps: forming a second metallized tie layer on a second surface of the non-metallic spacer component opposite the first surface, wherein the first metallized tie layer is separate from the second metallized tie layer; positioning the second surface of the non-metallic spacer component to mate with a metallic surface of the first component , the first component is either a metal or a non-metallic component with a metallised tie layer on the first component , and joining the second metallized tie layer with the mated metallic surface of the first component ; and positioning the first surface of the non-metallic spacer component to mate with a metallic surface of a second component , the second component is either a metal component or a non-metallic component with a metallised tie layer on the second component , and joining the first metallized tie layer with the mated metallic surface of the second component , wherein the joining of the non-metallic spacer component with the first component and with the second component uses metal to metal joining techniques. forming a first metallized tie layer on a first surface of a non-metallic spacer component , the non-metallic spacer component configured to join a first component and a second component ; and being characterised by the following steps: forming a second metallized tie layer on a second surface of the non-metallic spacer component opposite the first surface, wherein the first metallized tie layer is separate from the second metallized tie layer; positioning the second surface of the non-metallic spacer component to mate with a metallic surface of the first component , the first component is either a metal or a non-metallic component with a metallised tie layer on the first component , and joining the second metallized tie layer with the mated metallic surface of the first component ; and positioning the first surface of the non-metallic spacer component to mate with a metallic surface of a second component , the second component is either a metal component or a non-metallic component with a metallised tie layer on the second component , and joining the first metallized tie layer with the mated metallic surface of the second component , wherein the joining of the non-metallic spacer component with the first component and with the second component uses metal to metal joining techniques. forming a second metallized tie layer on a second surface of the non-metallic spacer component opposite the first surface, wherein the first metallized tie layer is separate from the second metallized tie layer; positioning the second surface of the non-metallic spacer component to mate with a metallic surface of the first component , the first component is either a metal or a non-metallic component with a metallised tie layer on the first component , and joining the second metallized tie layer with the mated metallic surface of the first component ; and positioning the first surface of the non-metallic spacer component to mate with a metallic surface of a second component , the second component is either a metal component or a non-metallic component with a metallised tie layer on the second component , and joining the first metallized tie layer with the mated metallic surface of the second component , wherein the joining of the non-metallic spacer component with the first component and with the second component uses metal to metal joining techniques. <EOS>