A method of manufacturing a preformed elbow insulation fitting includes applying an adhesive to an edge surface of each of a plurality of insulation gore components. After applying the adhesive, the plurality of insulation gore components are formed around a mold. When forming the plurality of gores around the mold, adjacent gores of the plurality of gores are adhered together to form a preformed insulation elbow around the mold. The preformed insulation embow can include a split line space between gore components running radially along a perimeter of the preformed insulation elbow. The preformed insulation elbow is then removed from the mold.