I have 5 or 6 55 gal drums, I am in the greenhouse business. I took an old fan from a green house, cut the blades down so it would fit in the drum, extended the shaft so it sits on top of the drum and reaches 3 in from bottom, put a bigger pully to slow it down from where it turned in the greenhouse, and now I have a mechanical mixer. I used an old fan from when we upgraded, and built a motor from several bad ones I had lying around. Total cost of mixer: one $11 55 gal drum. I mix 40 gal at a time, b/c when I put 8 gal of methanol on top of that it is almost full, then shoot it out into a 55 gal drum, then start on another, I can make a 40 gal batch in about 30 min, then make another, and let them all sit overnight. I turn my electric hot water heater on the next morning and boil it to about 150-160 for about an hour, then let it sit another night. The next morning I have two valves, one about 5 in above the floor and one right on the bottom. I open the top valve and hook my $25 Harbor freight pump, pump it through my final 10/2 micron filters and into my truck or holding tank.