A method for manufacturing a complex-shaped, elastomeric fuel tank for installation into a vehicle body cavity, the fuel tank comprising an upper portion and a lower portion, the upper and lower portions having complementary mating peripheral edges, the method comprising the steps of:
- providing an upper female mold section and a lower female mold section, the upper and lower female mold sections exactly duplicating a plurality of complex contours of an upper portion and a lower portion, respectively, of the vehicle body cavity into which the fuel tank will be mounted;
- forming the upper portion of said fuel tank using the upper female mold section, said step of forming including the steps of:
- coating a first ply of urethane elastomer onto the upper female mold section;
- applying a woven fabric over the first ply;
- coating a second ply of urethane elastomer over the woven fabric to encase the fabric between the first ply and the second ply;
- applying a first fuel-resistant film over the second ply to provide a first barrier to hydrocarbon fuels;
- coating a third ply of urethane elastomer onto the first fuel-resistant film to provide a first liner for the upper portion of the fuel tank;
- subsequently removing the first ply from the upper female mold section, thereby forming a composite defining the upper portion of the fuel tank;
- applying a tear-resistant fabric to a side of the first ply previously contacting the upper female mold section;
- applying a second fuel-resistant film over the tear-resistant fabric to provide a second barrier to hydrocarbon fuels;
- and
- coating a fourth ply of urethane elastomer onto the second fuel-resistant film to provide an outer ply to the upper portion of the tank;
- preparing the lower portion of said fuel tank using the lower female mold section, said step of preparing including the steps of:
- coating a fifth ply of urethane elastomer onto the lower female mold section;
- applying a plurality of layers of self-sealing material over the fifth ply in the lower female mold section;
- applying vacuum pressure to the plurality of layers;
- curing the plurality of layers while still in the lower female mold section at a temperature of at least 220.degree. F. and a pressure of at least 15 psi;
- coating a sixth ply of urethane elastomer over the plurality of layers of self-sealing material to encase the plurality of layers of self-sealing material between the fifth ply and the sixth ply;
- applying a third fuel-resistant film over the sixth ply after the plurality of layers have been cured to provide a third barrier to hydrocarbon fuels;
- and
- coating a seventh ply of urethane elastomer onto the third fuel-resistant film to provide a second liner for the lower portion of the fuel tank;
- and
- subsequently removing the fifth ply from the lower female mold section, thereby forming a second composite defining the lower portion of the fuel tank having peripheral edges;
- joining peripheral edges of the upper portion of the fuel tank with the peripheral edges of the lower portion of the fuel tank to form the fuel tank;
- applying at least one additional woven fabric and at least one additional ply of urethane elastomer to an interface of the joined peripheral edges within the fuel tank to form a splice between the upper and lower portions of the fuel tank;
- and
- allowing the fuel tank to cure.