Crucibulum

Crucibulum is the Medieval Latin word English took “crucible” from. It meant the little melting pot, and it also meant a night lamp, the same small vessel holding the same small fire, put to two uses. The figurative sense came out of the metal and not the other way round: a crucible was a pot for a very long time before it was a trial by fire.

This mod is the literal one. Vanilla asks you to keep two fires: the firepit melts, the forge smiths, and you walk between them. The 1.22 forge is the better fire — fuel types that matter, a bellows that drives the temperature — and it stands idle between heats. Crucibulum allows you to put a crucible in it!

<table style="border-collapse: collapse; width: 39.1089%; height: 141.367px; border-spacing: 10pxpx;" cellpadding="10px"> <tbody> <tr style="height: 20.1953px;"> <th style="width: 38.6882%; height: 20.1953px;">&nbsp;</th> <th style="width: 29.3%; height: 20.1953px;">firepit</th> <th style="width: 32.0131%; height: 20.1953px;">forge + crucible</th> </tr> <tr style="height: 20.1953px;"> <td style="width: 38.6882%; height: 20.1953px;">melts</td> <td style="width: 29.3%; height: 20.1953px;">yes</td> <td style="width: 32.0131%; height: 20.1953px;">yes</td> </tr> <tr style="height: 20.1953px;"> <td style="width: 38.6882%; height: 20.1953px;">ceiling</td> <td style="width: 29.3%; height: 20.1953px;">fuel burn temp</td> <td style="width: 32.0131%; height: 20.1953px;">1200 °C</td> </tr> <tr style="height: 20.1953px;"> <td style="width: 38.6882%; height: 20.1953px;">smith at the same fire</td> <td style="width: 29.3%; height: 20.1953px;">no</td> <td style="width: 32.0131%; height: 20.1953px;">yes</td> </tr> <tr style="height: 20.1953px;"> <td style="width: 38.6882%; height: 20.1953px;">700 units of tin bronze</td> <td style="width: 29.3%; height: 20.1953px;">6.6 coke</td> <td style="width: 32.0131%; height: 20.1953px;">5.4 coke</td> </tr> <tr style="height: 20.1953px;"> <td style="width: 38.6882%; height: 20.1953px;">keeping a melt liquid</td> <td style="width: 29.3%; height: 20.1953px;">same as melting</td> <td style="width: 32.0131%; height: 20.1953px;">a third of melting</td> </tr> <tr style="height: 20.1953px;"> <td style="width: 38.6882%; height: 20.1953px;">nickel (1325 °C)</td> <td style="width: 29.3%; height: 20.1953px;">yes</td> <td style="width: 32.0131%; height: 20.1953px;">no</td> </tr> </tbody> </table>

&nbsp;

The firepit keeps the top of the range. A crucible in a forge is clamped at 1200 °C, so nickel still wants a firepit, and iron is still bloomery work.

Using it

Right-click the forge with a crucible to set it in, or shift-right-click — either works, as at a firepit. Right-click a forge that has a crucible in it to open the crucible window; shift-right-click with an empty hand to take the crucible back out. Ore and ingots go in through the window, and fuel goes on the forge the way it always has.

Smithing is untouched. A forge holding an ingot hands it over on a plain right-click exactly as it always did, and burns fuel at exactly the rate it always did.

The window

Laid out like the firepit's, because that is the one you already know. What it adds is the blend — each metal's share of the melt, quoted in the same units alloy recipes are written in, so twenty nuggets and one ingot weigh the same:

Copper 90% · Tin 10%
Will create 100 units of Tin bronze

Get the ratio wrong and vanilla tells you nothing at all, which looks exactly like a mix that is fine but cold. Crucibulum is a little clearer:

Copper 40% · Tin 60%
These will not combine
Tin bronze needs Tin 8-12%, Copper 88-92%

If the metals make no alloy at all it says they will not combine and quotes no ratio, rather than sending you after a recipe that does not exist. The temperature line carries what it is climbing towards — 900°C · melts at 1084°C — and drops the target once the metal is going. All of it is in the block info too, so you need not open anything for the common case.

Heat

A charge comes up to temperature, melts, and is then held. Each is different work for the fire.

The climb is proportional to how far there is left to go, so it is brisk while the crucible is cold and eases in over the last stretch. More metal climbs more slowly — the same fire poured into a brim-full crucible takes over three times as long as into an empty one. While the charge is actually melting the temperature all but stops rising, which is latent heat: the energy is going into changing the metal's state rather than raising its temperature.

• 20 nuggets — 61s to temperature, then 30s melting
• 60 nuggets — 92s, then 90s
• 140 nuggets — 153s, then 210s (a full 700-unit crucible)
  
  

Tip cold ore into a hot crucible and you cool the whole lot, weighted against what is already in there — so topping up a nearly-molten crucible genuinely sets you back.

Once the metal is liquid the fire is only replacing what the crucible loses to the air, so holding a melt costs about a third of what making it did. One lump of coke lasts 67 seconds while melting and 190 while holding, against 240 in an empty forge. Let it go solid and it is a full melt to do again.

Fuel

What you burn decides what you can melt, unaided:

• coke — 1200 °C, up to cupronickel
• charcoal — 1150 °C, up to copper
• bituminous coal, anthracite — 1100 °C, up to copper
• lignite — 1000 °C, up to silver
• contaminated coal — 900 °C, up to bismuth bronze