The cannon furnace is used when repairing dwarf multicannons within the Artisans Workshop. It is obtained after removing the broken fuse box and broken flint from a broken cannon furnace. The fuse box and flint should be repaired, then re-added to the furnace to make a repaired furnace. Once repaired, it should be placed on top of the base, stand and barrel in the middle of the room.
This item cannot be taken outside of the repair area.