Sharpen and care for your tools

Grind edges on a wet stone and keep wood and cord dry so your tools outlast the seasons.

easy⏳ an afternoontradition — not yet hand-tested

A dull tool is slow, and worse, it is dangerous: you push harder, and hard pushes are what slip. A sharp edge cuts with light pressure and goes where you point it. And a tool you made in a day can serve for years — but only if you keep water out of its wood, its cord, and its edge. Sharpening and care together take less time than making one new tool.

Learn this once and every tool you ever own, stone or steel, gets better.

You need

• A flat, gritty stone — sandstone is ideal. You will know it: it feels like sandpaper and scratches other rocks. This is your grinding stone.
• A smooth, fine stone — a flat river-worn pebble. This is for finishing, the last light strokes.
• Water — a puddle's worth, kept on the grinding stone the whole time.
• Fat or oil — animal fat, tallow, or nut oil, for feeding wooden handles.
• A dry storage spot — off the ground, under cover, with air moving. A shelf of sticks lashed inside your shelter is enough.

Steps

1. Read the edge. Hold the tool edge-up toward the light and look straight down at it. A truly sharp edge is too thin to see. Any spot that flashes a bright line of reflected light is dull or chipped — that is where you grind.
2. Wet the stone and keep it wet. Splash water on whenever it starts to dry.
3. Set your angle. Lay the blade flat on the stone, then tilt it up about a third of the way to upright — roughly 20 to 30 degrees. Steeper for an axe that hits wood, shallower for a knife that slices.
4. Grind in circles or long push strokes, keeping that exact angle. Count your strokes: 20 on one side, then 20 on the other, so the edge stays centred. Repeat until the bright dull line is gone.
5. Hold the angle steady. This is the whole skill. Rocking your wrist rounds the edge and makes it duller than when you started. Lock your wrist; move from the shoulders.
6. Finish on the smooth stone. Ten light strokes per side at the same angle. This polishes away the tiny ragged scratches the coarse stone left.
7. Test on wood, never skin. A sharp edge shaves a thin curl off a soft stick with almost no pressure. Do not run a thumb along the edge.
8. Feed the wood. Rub fat or oil into handles and wooden tools until they stop drinking it in — once a month or so, more in dry weather. It fills the pores so water cannot get in and crack the wood.
9. Dry the cords. Lashings and cordage that got wet should dry slowly near — never over — the fire. Then tug-test every lashing and retighten what gives.
10. Store everything up and under. Tools go off the ground, under cover, edges wrapped in a slip of bark so nothing (and no one) meets them by accident.

Watch out

• Grinding dry clogs the stone with dust and glazes it smooth, and on metal tools it overheats the edge. Water is not optional.
• Testing the edge on your thumb is a tradition of scars. Test on a stick.
• An edge ground too thin looks impressively sharp and chips on the first blow. Stone edges especially want a slightly blunter, sturdier angle than you would guess — when in doubt, go steeper.
• Damp ground destroys tools quietly. Wood laid on soil rots and cord grows mould within weeks. Off the ground, always, even overnight.
• Fast drying splits wood. A soaked handle set right beside the flames will crack by morning. Shade and moving air, slowly.
• A loose lashing found late fails in mid-swing. Make the tug-test part of picking any tool up, not a special occasion.

How it works

An edge is just two flat faces meeting in a line thinner than a hair. Grinding drags thousands of tiny grit teeth across the face, scraping it back until the meeting line is thin again. Water floats the ground-off dust away so the grit keeps biting. And fat in wood works like wax on a boot: water beads off instead of soaking in, so the wood never swells, shrinks, and cracks.