Below is a walkthrough for the Upgrade Weapons task in Rune Factory 5.
Client: Randolph
Objective: Upgrade a weapon
Reward(s): Bronze x1
After accepting this request from the Task Board, Randolph will task you with upgrading a weapon. To do this, head to your forge then select the upgrade a weapon option. You’ll then need to select a weapon to upgrade along with a material. Something as simple as scrap metal should do the trick which can be found from smashing giant rocks with the hammer. Once the weapon has been upgraded, return to the Task Board to complete the task.