Abstract: In a cartridge filter having a support member defining the shape of the cartridge filter and a filter media contained within the support member, a method of constructing a sealable end cap for the cartridge filter comprising the steps of placing a seal element in the forming cavity of a mold, the cavity adapted to receive one end of the support member therein, and thereafter inserting the end of the support member into the mold cavity. The mold forming cavity is then filled with a molten thermosetting epoxy material so that upon hardening, the epoxy material forms the cartridge filter end cap while simultaneously partially encapsulating the seal element, thus mechanically securing the seal element to the end cap.