Foundry research stuck at 99% (Factorio Space Age)

On Vulcanus in Factorio: Space Age, Foundry is a trigger technology. The tech card says Researched by: Craft tungsten carbide. Players craft stacks of carbide, see Researched: 99% (or even 100%), and still get Foundry (Unavailable) with Start research greyed out. That is almost never a bug—and owning carbide in your inventory is not the missing step.

The short answer

Your tungsten carbide craft trigger is done. Foundry still has a second gate: the prerequisite technology Calcite processing. Unlock that by mining calcite on Vulcanus. When Calcite processing finishes, Foundry completes automatically—you do not click Start research.

Why the UI looks so misleading

Space Age packs several Vulcanus unlocks into trigger techs (mine X, craft Y) instead of science packs. The Foundry detail card only advertises the craft line in Researched by. It does not shout the second prerequisite on that same summary line, so the progress bar fills from carbide while the node stays red / Unavailable.

Zoomed or single-line views of the tech tree make this worse: you can follow Vulcanus → tungsten and miss the sibling branch. Foundry has two inbound arrows. Both must be green.

Read the labels carefully:

Unavailable + grey Start research → prerequisites or trigger not fully satisfied; you cannot queue it like lab science.

A nearly full bar after crafting carbide → the craft side is satisfied; look upstream in the Vulcanus tech tree.

Red Foundry node with a yellow neighbor → that yellow tech (Calcite processing) is what you still need.

Open the technology tree, zoom out so both parents of Foundry are visible, and finish the unfinished one.

Fix it: unlock Calcite processing

1. Find calcite on Vulcanus (resource patches on the volcanic surface—often near your early outpost once you scout).

2. Mine it—by hand or with a mining drill. The Calcite processing trigger is a mine action, not “have calcite in inventory from a chest.”

3. Watch Calcite processing complete in the tech tree (the yellow node turns green).

4. Foundry should flip to researched and unlock the building plus casting recipes (molten metals, cast plates, gears, and the rest of the effect list).

If you somehow already have calcite sitting in logistics from a friend, a wreck, or a weird transfer but never mined it yourself for this force, go mine a patch once so the trigger fires.

What does not finish Foundry

Holding tungsten carbide in inventory. Possession is not the trigger; crafting was, and you already did that.

Crafting more carbide “just in case.” Extra stacks will not clear Unavailable if Calcite processing is still locked.

Clicking Start research. Trigger techs auto-complete; the button stays dead on purpose.

Looking only at the Foundry detail card or a single-line tree slice—zoom out and check both prerequisite arrows.

Placing or crafting salvaged / early foundries you got from ruins or odd unlock order. Having a foundry item in a chest is separate from finishing the Foundry technology node for the full casting suite.

Quick checklist

Crafted tungsten carbide at least once (assembler or hand).

Researched Calcite processing by mining calcite.

Confirmed Foundry’s prerequisite arrows in the tech tree, not only the Researched by craft line.

No expectation that Start research must be pressed.

FAQ

It says 99%—is the game broken?

No. That partial bar is the classic “carbide done, calcite prerequisite not done” look. Official replies on the Factorio forums treat this as missing Calcite processing, not a failed craft trigger.

I mined calcite and nothing happened

Confirm it was calcite (not stone / coal lookalikes in a busy hotbar), that you are on the same force/save, and that Calcite processing is the node that lit up. Then re-open Foundry—it should complete without a lab.

Do I need science packs for Foundry?

Not for this unlock. Foundry on Vulcanus is trigger-based. Later metallurgy / planet science is a different story once the foundry loop is running.

Where does this fit on a first Vulcanus trip?

Mine calcite early while you set up power and the cargo pad. Do not tunnel-vision tungsten carbide alone. Pair this with the First trip to Vulcanus packing guide so acid, bots, and the silo kit are ready when casting comes online.

Related Beltworks guides

Continue with First trip to Vulcanus: what to bring, How to board a rocket and travel to a space platform, and Finding Space Age and Factorio 2.0 blueprints for foundry and casting layouts on Beltworks.

Method and sources

This matches repeated Space Age help threads (including staff answers): Foundry stays Unavailable after crafting tungsten carbide until Calcite processing is unlocked by mining calcite. Screenshots in this guide show the misleading Foundry card and the two-parent Vulcanus tech-tree layout that single-line views often hide.