The forge is the deluxe version of the firepit. It does all the things a firepit does except it has five slots to put items into, eg. heat up metal for smithing. Also instead of wood or peat, it is powered by coal or charcoal, and can be heated to higher temperatures than the firepit.
To construct, place a stone block (any type will do) as a bottom, then 4 blocks around the center of that block, creating a hollow area. Throw nine pieces of coal, or right-click with charcoal 8 times inside on the bottom stone. Finally light it with a firestarter and viola! You have a forge.
The forge does not spread fire, but requires a roof when raining. Keep in mind, the forge still requires access to open-air (eg. you could build a chimney with a bend to allow access to air without exposing it to rain). A bellows can be added to increase the temperature of the fire.
A Slideshow Of The Process
The forge's GUI is a little confusing at first glance but is fairly simple in reality. Here we have the slots numbered 1-15.
From Left to Right:
- First we have the temperature gauge.
- Slots 1-5 are the input slots
- Slot 3 burns the hottest followed by slots 2 and 4, then slots 1 and 5.
- Slots 6-10 are the fuel slots, they accept charcoal and coal as fuel.
- The centre piece is always used first and when it's gone the outer pieces fall inward.
- Slots 11-14 are the tool slots
- Right now their main use is holding ceramic molds to catch the liquid metal. Without a ceramic mold any liquid metal created is lost.