Crucible

An open brick pot that sits over a Firebox (or lava). It's where you make steel, melt metal and mix alloys, and it's the one hot vessel you can measure and automate.

Crafting

Small Crucible

B   B
B B B

Large Crucible

B   B
B   B
B B B

B is a Brick.

Small vs. large

The only difference is weight: a large crucible is ten times as heavy. A small crucible closes most of the gap to its fire in about 2 seconds, overshoots easily, and is hard to hold steady. A large one takes about 20 seconds but holds a temperature almost on its own. Both settle at the same temperature on the same fire. Some processes (steel especially) have a max rate, and a small crucible on a full fire may simply climb too fast to satisfy it. See Heat.

A Refractory Lining makes a small crucible behave more like a large one.

Using it

• Right-click with an item to put it in. It holds two items.
• Right-click with an empty hand to take the last one back out. It comes out at the crucible's temperature and starts cooling at once.

Whatever is inside sits at the crucible's temperature. The crucible doesn't know what you're making. It just gets hot, and the items do whatever they do at that temperature (see JEI's Thermal process pages).

Making things

Put in the ingredients and hold the temperature inside the band. For example, an Iron Ingot + Charcoal becomes a Steel Ingot. See Making Steel. Let it get too hot and the batch is ruined (iron becomes Burnt Iron).

Melting

Ores, raw metal and ingots melt into the crucible's tank once they're hot enough. Fill an Ingot Mold or Bullet Mold by right-clicking the crucible with it. Melt two metals in the right proportions and you get an alloy. See Casting and Alloys.

The tank holds 1296 mB, nine ingots' worth (144 mB an ingot). If it's full, extra metal that melts is lost.

Building around it

The crucible notices what's built against it:

• Insulation blocks against its sides help it hold heat.
• Dampers against its sides let you dump heat on demand.
• A Bimetallic Strip against it makes a simple thermostat.
• A Temperature Sensor on any face lets a Controller read it.
• A Powered Bellows goes against the firebox, not the crucible.

Reading it

Jade shows how hot it is in words, or as a figure with a Thermometer in your inventory. It also shows how many sides are insulated and what's inside.

Because it's open, a crucible can always be watched. The sealed furnaces can't; see Furnaces.