a molded assembly comprising a wall made from a plastic sheet that is pliable at a first elevated temperature . a body having a penetrating portion and a connecting portion forms an aperture in the wall , the connecting portion extends through the aperture and is made from a material resistant to melting at the first temperature . the connecting portion is made from a material that will at least partially melt at the first temperature . the connecting portion engages one surface of the wall , whereby when the wall is raised to the first temperature , the connecting portion partially melts and becomes integral with the wall when returned to ambient temperature .