100 Days at Sea Sawmill — Recipe, Unlock, Why Two

What it is

The Sawmill is a structure you build on the raft, not a location you sail to. It converts raw wood into wooden planks: three planks per cycle, and it never runs dry. Each cycle takes a few seconds. Planks are the early bottleneck — furniture, walls, the rest of the raft — so a mill that prints them while you keep harpooning is the first structure that changes the shape of a run.

The recipe is one of only two on this site with a tested source. Pro Game Guides' beginner guide, re-read July 26, 2026, publishes 10 Wood + 2 Metal. The other tested recipe is the Magnet at 30 Metal + 10 Wood. For everything else, the in-game build menu is the source until we have tested it ourselves. Full context sits on the items and structures page.

Where it sits on the Bonfire ladder

The Sawmill unlocks once the Bonfire hits level 3. That is also the first genuine wall in the game. Official badge statistics: 81.1% of players reach Bonfire 2 and only 55.1% reach Bonfire 3. Nearly half of everyone who has ever set sail never unlocks this building. Clearing that gate is most of what separates a run from a false start.

The next documented gate is Bonfire 4, where the Magnet comes online. The Sawmill is not that building — it is the reason you are still alive to see it. Almost everything that ends a beginner's run happens before the Sawmill is up.

When to prioritize it

Pro Game Guides' beginner guide is the only walkthrough of this game we've found that names a build order and puts numbers on it. The opening is:

1. Harpoon everything. Wood and Metal drive every craft, and both arrive floating past the raft.
2. Bonfire to level 3 — the unlock condition.
3. Sawmill ×2. At least two on the raft, more in co-op.
4. Then a Crab Trap for passive food, then the rest of the six-building spine: Map Radar, Auto Turret, Magnet, Radio.

The day guide files this as Days 1–3. The islands page is equally blunt about leaving the raft: stay home until the Sawmill is up and a Crab Trap is set. You have nothing an island can meaningfully add yet, and a dead Bonfire while you are away is an Angler Fish.

Why two

Slow planks are the #1 early bottleneck. The tested advice is to run two rather than one, because a second Sawmill is cheaper than the days you lose waiting. That is the whole argument. We do not have a published plank-per-minute figure, a cap on how many mills a raft can hold, or a recipe that changes with Bonfire level — so those stay off this page.

FAQ

• What does the Sawmill do in 100 Days At Sea?

  It converts raw wood into wooden planks — three planks per cycle, forever. Each cycle takes a few seconds. Slow planks are the single biggest early bottleneck, which is why it is the first structure in the tested build order.

• How do you unlock the Sawmill?

  Push the Bonfire to level 3. That is the unlock condition, and it is the first real filter in the game: 81.1% of players reach Bonfire 2 and only 55.1% reach Bonfire 3.

• What is the Sawmill recipe in 100 Days At Sea?

  10 Wood + 2 Metal, per Pro Game Guides' tested beginner guide. That is one of only two structure recipes on this site with a tested source; the other is the Magnet at 30 Metal + 10 Wood.

• Should I build more than one Sawmill?

  Yes. The tested advice is to run two of them rather than one — at least two on the raft, more in co-op. A second Sawmill is cheaper than the days you lose waiting on planks.

• When should I build the Sawmill?

  In the first days. The Day 1–3 opening is: harpoon everything floating, push Bonfire to level 3, then build the Sawmill. Stay on the raft until it is up — a dead Bonfire while you are away is an Angler Fish, and you have nothing an island can meaningfully add yet.