Elongate tubular structures

An elongate tubular structure comprising:

• a) a first tubular structure comprising:
• 1) a first sheet metal having a machine direction, said first sheet metal being convolutely wound about a first longitudinal axis, said first sheet metal having a tail portion;
• and,
• 2) wherein said tail portion of said first sheet metal is disposed upon and bonded to an immediately subjacent convolution of said first sheet metal to form said first tubular structure;
• b) a second tubular structure comprising:
• 1) said first sheet metal being convolutely wound about a second longitudinal axis, said first sheet metal having a tail portion;
• and,
• 2) wherein said tail portion of said first sheet metal is disposed upon and bonded to an immediately subjacent convolution of said first sheet metal to form said second tubular structure;
• c) wherein a first end of said first tubular structure is matingly and fasteningly engaged to a first end of said second tubular structure.