Oh, um. An athanor. It's a type of furnace that can maintain a specific, steady heat for a while.

[ it's not quite the same as this one but whatever, he's worked with blacksmithing tools before. and the duck is here to supervise! ]

If you can get the raw materials to smelt and refine for the arrowheads somehow, that should be enough? Unless you just wanted copper ones. There's plenty of copper already in here to work with, so I probably wouldn't mind whatever excess you had on your farm in that case...?