Minecraft wiki entry for Item_repair, associated text: The repaired object is never enchanted even if both items were to have the exact same enchantments, with the exception of curse enchantments, which are transferred to the repaired item. Therefore, using a "junk" item in a repair may sometimes be useful for removing an unwanted enchantment from an item prior to enchanting it again. Tools made of different materials (for example, a wood and a stone pickaxe) cannot be combined.