Abstract: A method for producing a tubular insulator comprising providing a tubular insulator including a longitudinal tubular structure defining a first tubular end, a second tubular end and a central tubular structure between the first tubular end and the second tubular end. The longitudinal tubular structure further defines a longitudinal bore having a generally uniform first internal diameter generally throughout the longitudinal tubular structure including through the first tubular end and through the central tubular structure and through the second tubular end.