The strong smelting urn (full) is an item made by filling a strong smelting urn while smelting or superheating bars. It can be teleported to Ernie by clicking it, giving 250 Smithing experience. A full urn can also be given to Ernie manually by using the item on him, or through a chat option while having a full urn in the inventory. Full urn can also be teleported automatically by toggling auto teleport current skilling urn when full option on under Inventory options in General gameplay settings.
Players can also use an urn enhancer unlocked at level 24 Invention to get 25% more experience.
Players may only have 10 full urns at a time without teleporting them. If players have more than ten urns in their bank, inventory, and Beast of Burden combined, then they will not automatically fill up the 11th.