Forget finding a length of pipe to slip over the handle of the puny wrench you’re using. If you need some extra torque, grab this two-foot adjustable wrench from Olympia Tools.
To make this monster they drop-forge alloy steel into a die, then harden and temper it. They precision-machine the jaws, and to make it pretty and corrosion-resistant they chrome plate and polish it. The end result is a wrench that can be used to spin fasteners up 2-1/2″ wide.
You’ll pay $40 to $45 after shipping for this wrench.