Abstract: A cable, which may be a fiber optic cable, includes a plurality of conductors which are twisted together. A tape with a layer of superabsorbent powder thereon, is wrapped around the conductors. A sheath is formed around the outside of the tape. If a leak should occur, the superabsorbent powder absorbs moisture and expands to block further entry of moisture into the cable. The tape is formed by applying a layer of adhesive to a strip of flexible material. The adhesive is advantageously applied in a helical pattern which is spaced from longitudinal edges of the tape. The superabsorbent powder is then applied to the adhesive. A suction head removes excess superabsorbent powder from the tape. The tape is then wrapped around the conductors of the cable. The adhesive may be a sealant material which is applied to the conductors before they are wrapped with the tape.