There are as many varieties of oil transfer pumps as there are industries in which they are used. Regular bulk oil transfers are performed on a regular basis in the petroleum, automotive, heavy industrial and energy industries, not to mention edible oils in the food industry. This DIY oil transfer pump method is easy, handy and instantly useful in a myriad DIY oil transfer scenarios.
The stickiness of lubricating oil that helps it lubricate engines and machinery on the other hand makes it difficult to clean up. Therefore, the transfer equipment is usually committed to the one system where it is used. Oil's higher viscosity also doesn't work with centrifugal pumps. So positive displacement systems such as gear pumps, piston pumps and peristaltic pumps prevail. One of the other major issues with oil transfer activities is environmental--working with oils invariably leads to drips and spills. All these factors result in specialty oil transfer equipment that is prohibitively expensive for the occasional user.
This DIY oil transfer system segregates the pumping power source from the actual oil-wetted pumping mechanism. It uses a common wet-dry type shop vacuum to energize a completely separate oil transfer system that can stay oily between uses, saving huge amounts of time an oil transfer is performed.
Purchase two 5-gallon white plastic paint buckets with gasketed covers. You will also need a 15-inch by 20-inch commercial cutting board to bolster the bucket cover and the bucket interior; two plastic 1-1/2-inch NPT pipe thread by 1-1/2-inch hose barb fittings; a 4-foot length of 1-1/2-inch I.D. high-density polyethylene vacuum tubing; and a 2-foot length of 2-inch I.D. tubing. Cut off the top of one of the buckets so it fits cleanly in the other. This will strengthen the outer bucket to sustain vacuum pressure. Cut a circle from the cutting board with a diameter equal to the flat indentation in the bucket cover. Place it on the top of the cover. Bore two 1-3/4-inch holes in the top of the cover and cutting board assembly with a flat wood bit. Cut three ¾-inch lengths off the 2-inch diameter tube to use as nuts on the NPT threads of the two fittings. Fully thread a piece on both fittings, thread the fittings through the cover and thread on the other tube pieces, one short and one long as locknuts inside the cover. The long 2-inch tube section serves as both the oil fill and oil discharge tube inside the bucket, depending on the step in the transfer. It should go down from the cover to the lower corner of the bucket in a curve, yet without kinking.
Push the 4-foot polyethylene tube onto the fitting that has the long inner tube inside the bucket. Turn on the wet-dry vac and stick the suction hose end onto the stub fitting. Confirm strong suction on the open 4-foot oil suction tube, and stick it into the oil being transferred. Watch the oil level through the side of the bucket. You should be able to withdraw about 4 gallons of oil before switching to the discharge side of the wet-dry vac and reversing the process into the receiving tank.
