Just a thought, as I see you've bought a new tank.
I've had good luck hanging the tank up about 3' off the ground, between two trees or an a-frame, filling it about half full of hot water, dropping in some lug nuts, putting 3 or 4 ounces of dish washing liquid in, and swinging it side-to-side and back-and-forth.
Tie a lenght of rope to each end so you have something to grab hold of. It makes it easy to twist and to bring it to an abrubt stop, causing the lug nuts to really move around.
Alot of the time , by the time you finish you'll also know if there are any really rusty spots in the tank, because you'll see a leak.
