It may also be oiled or greased for a degree of waterproofing. To increase corrosion resistance, the surface may be oiled, lacquered, or waxed. Metal mortars are kept lightly oiled. The plastic stopcocks are at most lightly oiled. The dough is repeatedly kneaded, flattened, oiled, and folded before proofing, creating layers. Leather can be oiled to improve its water resistance. Some of them may be heated, oiled, or wrapped in cloth. The women usually minded the four machines and kept the looms oiled and clean. Usually the screw and nut are also oiled for lubrication. Ultimately, of oil impacted of U.S. beaches, and over of oiled material were removed. Reportedly, they were also cultivated in "specularia", cucumber houses glazed with oiled cloth. Gracie also claimed Zulu was oiled up with vaseline in order to impede his grip. Treating with an oiled coating enhances the protection offered by the bluing. It, too, must be oiled to provide any significant rust resistance. Speedway workers oiled and rolled the track prior to the gates opening to the public.