A furnace that runs on water instead of coal - feed it Concrete Powder of any color, keep it wet, and it churns out solid Concrete on its own.
| Fuel | Powders It Hardens |
|---|---|
| Water Bucket | 100 |
| Water Bottle | 20 |
Drop in a Water Bucket and you'll get the empty Bucket back once it's drained; a Water Bottle likewise leaves you with an empty Glass Bottle. Neither is consumed as a lump sum - the Mixer meters it out smoothly across every batch it processes.
Each individual Concrete Powder takes 100 ticks (5 seconds) to harden - exactly Blast Furnace speed, twice as fast as a plain vanilla Furnace. All 16 dye colors are supported; whatever color powder goes in, that exact color of Concrete comes out.
Built to slot straight into a hopper line: powder feeds in through the top, water fuel feeds in from the sides, and finished Concrete (plus any spent Bucket/Bottle) pulls out from the bottom - set up a hopper above and below and it runs itself indefinitely as long as the water keeps coming.