The blueprints for the insanely overpowered Korek Machete can be found on a rooftop in the north of the Slums. You should get this weapon as soon as possible to make the rest of the game easier. The Korek Machete does 500 damage, can take 35 hits and has 218 handling. The best part about it is that you can craft the weapon as often as you want and it only costs 10 alcohol and 20 metal parts (which are the most common materials and they can also be bought from merchants).
The Machete has 4 upgrade slots which you can use to increase the damage to over 600.