Abstract: A fuel tank comprises a rotationally molded tank wall having a recessed neck unitarily formed with the tank wall during the rotational molding process. The neck receives a correspondingly threaded cap so that a top surface of the cap remains substantially at the level of the tank wall surface when a stem on the cap is threadedly engaged in the correspondingly threaded neck of the tank. In addition, a process for recessing a fill cap in a fuel tank comprises rotational molding of a plastic powder to form a hollow body within at least two mold parts. An insert carried by the one of the mold parts forms a threaded neck recessed inwardly from the tank wall surface. In addition, the process molds a cap with a handle having a top surface at the level of the tank wall surface.