The simplest no-weld way to get water out of the bottom of an open top drum is to turn the drum over and lightly pound the bottom INWARD with a rubber or wood mallet. Once it is slightly concave you can turn the drum back over and elevate one side ever so slightly and any water in the drum will run to the lowest point on the "downside" of the bottom. A 1" board under the high side of the drum will maintain this when the drum is filled with oil.
Now using 1/2" PVC water pipe and 2 90° fittings "dry fit" an inverted U shape with as short a connecting pipe as possible between the two long legs of the U. Set it over the "low side" rim of the drum so one leg extends all the way to the bottom and cut the outside leg of the inverted U about 4" below the rim. "Dry fit" a PVC ball valve and add 3" of the pipe just cut off to the bottom of the valve. Add a 3' section of flexible clear hose that tightly fits over the bottom of THAT and secure with a hose clamp. Now glue/cement the PVC assembly together. Once the PVC cement is set fit the inverted U over the side of the drum so the low end sits exactly in the lowest spot on the bottom. The cut a section of (wood) 1x2 just long enough to tightly fit the inside diameter of the drum and cut a U shape on one end that tightly fits over the PVC pipe. Use this to wedge the bottom of the pipe in place on the bottom and if you wish make another to wedge it in place at mid drum.
Now..when the drum is at least half full you can open the valve and suck on the clear tube(held vertical) and when the clear tube fills with VO place it in a jug beside the drum and allow the siphon to establish itself...then close the valve once the level of VO in the drum is above the open end of the clear tube.
Now whenever you wish to drain the bottom of the drum just slowly open the valve and allow a quart of VO to flow into the jug.
Note: If you need to re-establish the siphon it is nice to have a 1' section of PVC pipe to slip into the clear hose so you don't have to suck on a dirty/oil hose end.