Insulated Furnace Utilizing Wood Ash

I constructed a furnace that's insulated using wood ash for the purpose of iron smelting. Insulating a furnace prevents heat loss from its walls, effectively raising the internal temperature. Dry wood ash, due to its fine particles separated by small air gaps, serves as an exceptional heat insulator by limiting heat conduction. To create a double-layered wall for the furnace, I crafted clay walls with an intervening space that I then filled with wood ash collected from various fires. The clay had to be entirely dry beforehand to ensure that the ash remained dry, preserving its insulation capabilities.

During the iron smelting test, the furnace yielded 34g of iron from 10 ore charges. The smelting process started off efficiently but encountered blower issues towards the end due to a broken housing. Despite this setback, the furnace's design shows promise, considering it achieved the third-best smelting result I've achieved in a natural setting using primitive tools and materials. I plan to repeat the process after I've replaced the faulty forge blower.