Your weapons, armor, and tools slowly degrade as you use them in Valheim. When they reach zero, you’ll see that they now have a red line underneath them, and you cannot equip them anymore. Luckily, rather than consistently wasting more resources to craft new ones and tossing these items away to deteriorate in the forest, you can repair them and make them brand new.
To do this, you’ll need first to craft a workbench. However, if you’ve been creating advanced tools like a bow, flint spears, and advanced weaponry, you’re likely extremely familiar with the workbench. Any time you want to repair your items, you need to have on available, so having some wood and a hammer on your character while you’re wandering through a biome is never a bad idea. Find a flat piece of land to set it down, and then create a quick shelter. The one slightly annoying part of using the workbench in the wild is using it underneath the shelter, so you’ll need a bit of wood to craft an indoor area.
After you’ve created it, approach the workbench and click the interact button (default ‘e’ key) to use it. The first menu that appears will be for all of the weapons, armor, and tools you craft. On the left side of the menu will be a small hammer, and if you highlight over it, you’ll receive the option to repair anything you have equipped that is slightly damaged. Even if that item has been partially used, you can choose to repair it, and the workbench fully restores it.
You can choose to return to your workbench at any time to do this. From what we could tell, there was no resource requirement. The only requirement has been a workbench inside a shelter, which can be a little difficult to have, especially when you’re trying to survive.