Patent ID: 7850890

Claim:
A method of manufacturing a fuel tank, comprising the steps of: providing a first polymeric body having an inner surface terminating at a free edge with a lip extending continuously around a perimeter of the first body and having a first mating surface and a shoulder extending around the perimeter of the first body, and having a first barrier layer of a polymer substantially impervious to fuel vapors and different than the polymer of the first body, adjacent to the inner surface of the first body and extending around the shoulder; providing a second polymeric body having an inner surface terminating at a free edge extending around a perimeter of the second body and having an outer second mating surface adjacent to the free edge of and extending around the perimeter of the second body, and having a second barrier layer of a polymer substantially impervious to fuel vapors and different than the polymer of the second body adjacent to the inner surface of the second body and extending over the free edge of the second body; disposing the lip and shoulder of the first body adjacent the free edge of the second body with the first mating surface and first barrier layer of the first body engaging the second mating surface and second barrier layer respectively of the second body to define a fuel cavity; and forming at least one weld between the first mating surface and the second mating surface and at least one weld between the first barrier layer and the second barrier layer to join the first and second bodies together and the first and second polymeric barrier layers together to provide a substantially continuous polymeric barrier layer surrounding the fuel cavity.