I'm aware the anvil combines an item with its base materials to repair it. What are the base materials of chainmail so I can repair my Respiration I Chain Helm?
You can repair a chain armor with iron ingots.
Here's the wiki paragraph:
Anvils can also repair a piece of armor using units of that armor's base material. Chain armor can be repaired in this manner by using iron ingots.
There are three different answers to this question:
- For use in anvil repairing, iron ingots are used.
- For use in crafting table repairing, another peice of the same armor must be used.
- For use in crafting the armor, fire must be used (unobtainable in Survival).
To obtain Chainmail armor, one must either kill a mob wearing such armor or trade with villagers.