In the photo below: Water beaded up on the surface of a Cold Steel 13" Kukri Machete (left) and a Wetterlings Forester's Fine Axe (right) that have been coated with wax from a paraffin candle.
(click to enlarge)
For a durable, water repellant finish on your machetes and axe heads, try rubbing a common paraffin-wax candle on them. The wax stays on longer than traditional protectants like gun oil, mineral oil, or petroleum jelly, plus, it won't rub off inside your pack or sheath as easily as traditional oils do.
TIP: It isn't necessary to coat all of the metal with the wax to do this. Just cover most of the surface and rub it in with your fingers. The wax rubs on easily, and once on, provides superior wet weather protection.