Woodworking and Joinery

Difficulty: easy to begin, decades to master. The most transferable skill here. Prerequisites: a cutting edge, and a way to keep it sharp. Stone, bronze, or iron will all do — see the note below.

On tools, since the roadmap puts this page in Tier 0 and iron in Tier 2: you do not need iron to start. Neolithic carpenters built jointed timber structures with polished stone axes and adzes, and the Bronze Age built ships and temples with bronze chisels — see copper and bronze, which is both easier and earlier than iron. Fire and an adze will hollow a log; stone will fell a tree.

Iron edge tools are enormously better and you should get them as soon as you can. But treat them as an upgrade to this craft, not a prerequisite for it, or you will spend a year waiting for a bloomery before you build a workbench.

Interactive figure, Fig 6 · Floating Panel: turn the moisture knob from oven-dry to soaked and switch flat- and quarter-sawn stock to watch the floating panel widen and narrow in its grooves, its length staying put, while the glued twin splits as it dries. A code-drawn explanatory model built from this guide's numbers, for orientation only; it is not an equipment drawing or a procedure.

Why it matters

Wood is the universal engineering material of the pre-industrial world. Every waterwheel, gear, loom, press, ship, cart, bellows, roof, and printing press in this repo is made of it. Wood is strong, light, free, self-renewing, workable with simple tools, and repairable.

Nothing you build in this repository gets built without woodworking. If you can only develop one craft skill, this is arguably the one.

Understanding wood before cutting it

This is where modern knowledge helps most, because wood's behavior is counterintuitive and getting it wrong ruins work months later.

Grain and strength

Wood is a bundle of hollow cellulose tubes running along the trunk. It is enormously strong along the grain and weak across it.

• Never put a load across short grain. A chair leg with grain running crosswise snaps.
• Riving (splitting) beats sawing for strength. A split follows the grain naturally, so every fiber runs the full length of the piece. A sawn board cuts through fibers wherever the grain wanders. Riven oak is dramatically stronger than sawn oak of the same size — which is why traditional chair legs, ladder rungs, tool handles, roof shingles, and barrel staves are all riven, not sawn. It's also much faster with hand tools.

Movement — the thing that ruins furniture

Wood shrinks and swells with humidity, forever, for its entire life. It moves a lot across the grain (roughly 5–10% between soaking wet and oven dry), somewhat less radially, and almost nothing along the grain.

Consequences you must design around:

• A wide flat panel will change width by several millimetres between summer and winter. If you fix it rigidly at both edges, it will split.
• The solution is the frame and panel: a solid panel held in grooves in a frame, free to float. This one design solves the problem completely and is why every good door and chest is built that way.
• Never glue a wide board crosswise onto another board's face.
• Boards cup away from the heart. Quarter-sawn boards (cut radially, so the growth rings run edge to edge) move about half as much as flat-sawn and stay flat. Quarter-saw anything that needs to stay true.

Seasoning

Green wood is 50%+ water. It must dry before it's used for anything that must hold its shape.

• Air dry one year per 25 mm of thickness, as a rough rule, stacked with spacers ("stickers") between layers for airflow, out of sun and rain, off the ground.
• Seal the end grain (wax, paint, mud) — wood loses water 10–15× faster through the ends, and that differential is what causes end splitting.
• Dry too fast and it cracks and cups; too slow and it molds.

But green wood is a feature, not just a problem. It's far easier to split, carve, and turn. The whole tradition of green woodworking exploits this: rive and shape green, then let it dry to final shape. Better still, combine wet and dry deliberately — fit a dry tenon into a green mortise, and as the green wood dries it shrinks and grips the joint permanently tight. That trick joins chairs without any glue at all.

Choosing wood

Sapwood is generally non-durable, but heartwood durability depends strongly on species, tree, and exposure; the dark center is not automatically rot-resistant. For wet service, select heartwood from a locally proven durable species, exclude defects and sapwood, and still design for drainage, inspection, and replacement.

The tools, in order of what to make first

1. Axe — felling and rough shaping. Your first tool.
2. Froe and mallet — a wedge-shaped blade struck along a log's end to rive it. Cheap to make, and it's what turns logs into usable stock without a saw.
3. Wedges — for splitting big logs.
4. Drawknife and shaving horse — a two-handled blade pulled toward you while a foot-operated clamp holds the work. Fast, controlled shaping, and the shaving horse costs nothing but wood.
5. Adze — for hollowing and for surfacing beams.
6. Saws — rip saws (teeth like tiny chisels, cutting along the grain) and crosscut saws (teeth like knives, severing fibers). These are different tooth geometries and using the wrong one is miserable. Set the teeth alternately left and right so the kerf is wider than the blade and the saw doesn't bind.
7. Chisels and gouges — joinery and carving.
8. Braces, augers, and gimlets — boring holes. A spoon bit or auger clears its own waste.
9. Planes — a blade held at a fixed angle in a body, taking a controlled shaving. Roman planes are recognizably modern. Jack (rough), try (flattening long), smoothing (final), plus moulding and rebate planes for shaped work.
10. Lathe — see below.

Sharpening is the actual skill

A dull tool is dangerous, exhausting, and produces bad work. Sharpening is not a chore before the real work; it is the work.

• Grind on a coarse wet sandstone wheel to establish the bevel.
• Hone on progressively finer stones — sandstone, then slate, then a fine waterstone or oilstone, with water or oil to float the swarf away.
• Strop on leather charged with fine abrasive (rouge — see dyes and pigments) to remove the wire edge.
• Test on material, not your body: a genuinely sharp edge slices scrap end grain or paper cleanly without crushing. Look at the edge in bright light — a sharp edge is nearly invisible; a dull one shows a bright reflective line.
• Maintain a consistent bevel angle: roughly 25° for softwood paring, 30° for general work, 35° for chopping and hard timber.

See iron and steel for hardening and tempering the edges themselves — straw to bronze temper colors for edge tools.

Joints

The whole art is making joints that are strong, that accommodate wood movement, and that can be made with the tools you have.

Design principle: in timber framing, joints should work in compression wherever possible, with pegs only stopping things from pulling apart. Wood is much stronger in compression than a fastener is in tension.

Glue and fasteners

• Hide glue — boil hides, hooves, and trimmings (see leather and tanning) down to a syrup and dry it. Reheat with water to use. Strong, and reversible with heat and moisture, which means repairable — a real advantage over modern glues. Not waterproof.
• Casein glue — curd from sour milk plus a controlled alkali formulation. Properly made and cured casein glue can be more water-resistant than hide glue, but it is not universally waterproof and durability varies with recipe, biological growth, joint fit, and exposure. Test it and protect persistent wet joints mechanically.
• Pitch and resin — pine resin with charcoal and beeswax. Waterproof, brittle, good for sealing rather than structural joints.
• Wooden pegs (treenails) — dry hardwood pegs driven into matched holes. They move compatibly with timber and do not rust, making them excellent in many timber frames and boats. They are not a universal structural replacement for metal: choose pegs, nails, bolts, or straps from the joint's shear, tension, withdrawal, environment, inspection, and failure consequences.
• Iron nails and screws — expensive when hand-forged, and they rust and split the wood. Clench (bend over) nail points for real holding power.
• Wrought-iron straps and bolts — for the highest-load joints.

The lathe — the machine that makes machines

A lathe rotates work against a fixed cutting tool. It's the first machine tool, and everything precise descends from it.

• Pole lathe — a cord around the work, tied to a foot treadle below and a springy pole above. The work spins forward on the down stroke and back on the return, so you cut intermittently. Cheap, silent, portable, and entirely adequate for chair legs, bowls, and handles.
• Great wheel lathe — an assistant turns a large wheel driving the spindle continuously in one direction. Continuous cutting, much faster.
• Treadle lathe with flywheel — crank and flywheel give continuous rotation from one operator. See mechanical power.
• Water-powered lathe — for heavy work.

Why it matters beyond bowls: once you can turn accurate cylinders, you can make screws, gear blanks, spindles, wheel hubs, and eventually bored cylinders — and accurate cylinder boring is the actual prerequisite for steam power. A lathe with a leadscrew (a threaded rod geared to the spindle, moving the tool at a fixed rate) can cut screw threads mechanically, which is how you escape hand-filed threads and enter real precision engineering.

That transition — from wood turning to metalworking accuracy — is its own discipline, and it's covered in precision and toolmaking: making files, generating a true flat from three rough plates, cutting threads, and boring straight.

Things worth building, in order

1. A workbench with a flat top and a way to hold work — a vise, holdfasts, or pegs. Everything is harder without one, and most beginners skip it.
2. A shaving horse — free, and it makes drawknife work fast.
3. Storage and containers — boxes, chests, barrels.
4. A pole lathe.
5. Doors, windows, frame-and-panel work.
6. A timber-framed building. Cut all joints on the ground, number every piece with a scribed mark, then raise the frame in a day. This is how barns and cathedrals were built, and the numbering system is essential — a frame is a kit of hundreds of unique parts.
7. Machines — presses, looms, mills, and the printing press.

Coopering — worth calling out separately

Barrels are a genuinely remarkable piece of engineering: watertight vessels with no fasteners, no glue, and no sealant, held entirely by the compression of hoops against curved staves. They're strong, they roll (so one person moves 200 kg), they stack, and they're the standard shipping container of the world for two thousand years.

High-quality liquid-cooperage staves are preferably riven from suitable oak so the grain and rays run favorably; carefully sawn staves also exist, so riving is a quality method rather than an absolute rule. Staves are shaped with a hollowing knife and jointed on a long plane so their edges meet at exactly the right angle, raised into a rough cylinder inside a temporary hoop, then bent by wetting and heating over a fire before the final hoops are driven on. Charring the inside is what gives whiskey and wine their barrel character.

It's a difficult craft with a long apprenticeship, and it's worth the investment — without barrels you cannot store or ship liquids at scale.

Wood preservation

• Controlled surface charring (as in Japanese yakisugi) can improve weather and insect resistance in a correctly detailed cladding system. It does not make an assembly fire-safe; charred wood remains combustible, and structural or fire-performance claims require an assembly-level design and test.
• Oil and tar — linseed oil, pine tar, or a mix. Repeat annually.
• Keep it dry whenever possible. Wood can survive for centuries in stable, oxygen-poor waterlogged conditions, but “fully submerged” is not a general preservation method: oxygenated water, marine borers, microbes, and changing water levels can destroy it. Design submerged work for the actual environment.
• Design for drying. Detail buildings so water runs off and air circulates. Rot is always a moisture-management failure.

Failure modes

Safety

Edge tools are unforgiving. Keep your body and supporting hand outside the tool's projected path and know where it goes when it slips. “Always cut away” is not a usable universal rule—a drawknife is pulled toward its operator and controlled paring cuts may also point inward—so use the correct grip, stop, workholding, and body position for each tool. Never place a hand beyond an unsupported chisel cut. Green wood under tension can release violently. Lathes grab loose clothing and long hair; guard drives and isolate all motion before adjustment. Axe work needs a clear radius and a solid chopping block. Keep tools sharp because excess force reduces control, but do not treat a sharp edge as harmless.

Sources and limits

• The USDA Forest Products Laboratory's Wood Handbook chapter on biodeterioration shows that natural heartwood decay resistance varies widely by species and exposure; even durable wood still needs appropriate detailing.
• The UK Health and Safety Executive's woodworking-machinery guidance covers guarding, training, workholding, and safe access to dangerous parts.
• Joint strength, adhesive durability, fire behavior, and preservative performance depend on species, moisture, geometry, formulation, workmanship, exposure, and scale. Test representative assemblies where failure can injure people.

Era notes

Woodworking is the oldest craft — worked wooden spears from Schöningen are 300,000 years old, and there's a 476,000-year-old joined wooden structure from Zambia. Roman planes, chisels, and augers are recognizably identical to modern ones, and Roman joinery included mortise-and-tenon and dovetails.

Your knowledge advantages: understanding wood movement as a predictable physical property rather than a mystery (and designing frame-and-panel around it), draw-boring, why riven wood beats sawn, quarter-sawing for stability, casein glue where hide glue fails, and — the big one — the lathe with a leadscrew as the gateway from craft to precision engineering.