How do you unlock the Blast Furnace, and what does it craft?

The Blast Furnace is a late-game crafting station in Valheim used to smelt advanced metals like Black Metal and Flametal. To unlock the Blast Furnace, you must first defeat Moder, the fourth boss located in the Mountain biome. Moder drops Dragon Tears, a key ingredient required to craft the Artisan Table, which is necessary for building the Blast Furnace.\n\nTo craft the Blast Furnace, you need the following materials: 20 Fine Wood, 10 Iron, 20 Stone, and 5 Surtling Cores. Fine Wood can be obtained by chopping down Birch or Oak trees in the Meadows or Black Forest biomes. Iron is mined from Muddy Scrap Piles in the Swamp biome, and Stone is gathered from rocks found throughout the world. Surtling Cores are dropped by Surtlings in the Ashlands or found in Burial Chambers in the Black Forest.\n\nOnce you have the required materials, place the Artisan Table near your base. Interact with the Artisan Table to craft the Blast Furnace. The Blast Furnace must be placed on a solid foundation, such as stone or wood flooring, and requires a significant amount of space. Ensure your base has enough room to accommodate this large structure.\n\nThe Blast Furnace is used to smelt Black Metal Scraps into Black Metal and Flametal Ore into Flametal. Black Metal Scraps are dropped by Fulings in the Plains biome, while Flametal Ore is found in the Ashlands biome. These materials are essential for crafting high-tier weapons, armor, and tools, making the Blast Furnace a critical upgrade for late-game progression.\n\nOne common challenge players face is gathering enough Surtling Cores. If you''re struggling to find them, consider exploring multiple Burial Chambers in the Black Forest or farming Surtlings in the Ashlands. Another tip is to use a portal network to quickly travel between biomes, saving time when gathering resources like Iron or Fine Wood.\n\nTo maximize efficiency, place the Blast Furnace near other crafting stations, such as the Forge and Smelter, to create a centralized crafting area. This setup reduces the time spent running between stations and streamlines your crafting process. Additionally, always keep a stockpile of coal, as the Blast Furnace consumes it at a faster rate than the standard Smelter.\n\nIn summary, unlocking the Blast Furnace requires defeating Moder, crafting the Artisan Table, and gathering specific resources. Once built, it allows you to smelt advanced metals crucial for late-game gear. By planning your base layout and optimizing resource gathering, you can efficiently incorporate the Blast Furnace into your Valheim gameplay.