How do I craft a blast furnace and what does it allow me to smelt?

The Blast Furnace is an advanced crafting station in Valheim that allows you to smelt higher-tier metals like Black Metal and Flametal. Unlike the standard Smelter, the Blast Furnace is essential for progressing into the late game, as it unlocks the ability to craft powerful weapons, armor, and tools. To craft a Blast Furnace, you must first defeat Moder, the fourth boss in the game, and obtain the Dragon Tears she drops. These tears are a key ingredient for crafting the Artisan Table, which is required to build the Blast Furnace.\n\nTo craft the Blast Furnace, you will 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, while Stone is a common resource found throughout the world. Surtling Cores are dropped by Surtlings in the Ashlands biome or found in Burial Chambers in the Black Forest.\n\nOnce you have gathered all the materials, you must first craft an Artisan Table using 10 Wood, 2 Dragon Tears, and 4 Iron. Place the Artisan Table in a secure location, as it is required to build the Blast Furnace. With the Artisan Table in place, you can now craft the Blast Furnace. Open the crafting menu, navigate to the Crafting tab, and select the Blast Furnace. Place it near your other crafting stations for convenience.\n\nThe Blast Furnace allows you to smelt Black Metal Scraps and Flametal Ore into usable bars. Black Metal Scraps are obtained by defeating Fulings in the Plains biome, while Flametal Ore is found in the Ashlands biome. To smelt these materials, place them in the Blast Furnace along with Coal as fuel. Each Black Metal Scrap yields one Black Metal bar, and each Flametal Ore yields one Flametal bar. These bars are used to craft some of the best gear in the game, such as the Black Metal Sword, Black Metal Shield, and Flametal weapons.\n\nOne common challenge players face is finding enough Surtling Cores to craft the Blast Furnace. If you are struggling to locate Surtlings in the Ashlands, consider exploring Burial Chambers in the Black Forest. These dungeons often contain Surtling Cores in chests or as loot from enemies. Additionally, you can farm Surtlings by creating a Surtling spawner in the Swamp biome. Dig a trench near a Fire Geyser and lure Surtlings into the water, where they will die instantly and drop cores.\n\nAnother tip is to ensure your Blast Furnace is protected from enemy attacks. Place it inside a fortified base or surround it with walls and a roof. This is especially important in the Plains biome, where Fulings and Deathsquitos can pose a significant threat. Finally, always keep a steady supply of Coal on hand, as the Blast Furnace consumes it quickly when smelting large quantities of ore.\n\nIn summary, the Blast Furnace is a crucial crafting station for late-game progression in Valheim. By defeating Moder, gathering the necessary materials, and setting up a secure base, you can unlock the ability to smelt Black Metal and Flametal. These materials are essential for crafting top-tier gear, making the Blast Furnace a must-have for any Viking looking to conquer the toughest challenges in the game.