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Workshop: repair everything

Essential hand tools, fasteners, sharpening, basic metalwork, engines and spare parts.

1 Equip

The workshop: tools that need no power

Batteries die and power tools break. A good set of hand tools, kept sharp and oiled, repairs almost everything for the rest of your life.

Cut

  • Hand saw (crosscut) and a Japanese pull saw
  • Hacksaw + 20 spare blades
  • Bow saw or pruning saw for green wood
  • Axe and splitting maul
  • Utility knife + blades, tin snips

Drive and grip

  • Claw hammer, club hammer
  • Screwdrivers: flat, PH1, PH2, PZ2, Torx T10–T30
  • Combination and long-nose pliers, side cutters, locking pliers
  • Combination spanners 8–19 mm, adjustable spanner
  • Socket set, hex keys 2–10 mm

Shape and hole

  • Wood chisels 6, 12, 25 mm and a mallet
  • Files: flat, half-round, round, triangular saw file
  • Hand drill or brace with bits; cordless drill as a bonus
  • Centre punch, cold chisel, pin punches
  • Taps and dies M3–M12

Measure and hold

  • Tape measure, steel rule, try square
  • Spirit level, pencil, marker, chalk line
  • Bench vice, 4+ clamps
  • Calipers
  • Multimeter (how to use)

Maintain

  • Whetstones (coarse, medium, fine), strop
  • Wire brush, sandpaper assortment
  • Oil can, grease gun, penetrating oil
  • Soldering iron (12 V or gas), solder, flux

Land and garden

  • Spade, fork, rake, hoe, mattock
  • Scythe (cuts hay and grain for hours)
  • Wheelbarrow, pry bar, post-hole digger
  • Sledgehammer, wedges

Minimum repair kit

Buy old, buy good

Old forged hand tools from flea markets and sheds are often better steel than new cheap ones. A rusty saw, chisel or axe head cleans up with a wire brush, vinegar and a file. Cheap tools with soft steel will not hold an edge.

2 Join

Fasteners: screws, bolts and nails

Use the right driver, the right hole and the right size and fasteners hold for decades. Use the wrong one and the head strips on the first turn.

slottedflat blade PhillipsPH PozidrivPZ, has tick marks TorxT hex socketAllen key hex boltspanner
Most European wood screws are Pozidriv (PZ2). A Phillips bit in a Pozidriv screw slips and strips it. Press hard, keep the driver in line with the screw.

Metric bolt sizes

ThreadPitch (coarse)Spanner (hex head)Allen key (socket head)Tap drillTightening, grade 8.8
M30.5 mm5.5 mm2.5 mm2.5 mm1 Nm
M40.7 mm7 mm3 mm3.3 mm3 Nm
M50.8 mm8 mm4 mm4.2 mm6 Nm
M61.0 mm10 mm5 mm5.0 mm10 Nm
M81.25 mm13 mm6 mm6.8 mm25 Nm
M101.5 mm17 mm (ISO: 16)8 mm8.5 mm50 Nm
M121.75 mm19 mm (ISO: 18)10 mm10.2 mm85 Nm

Without a torque wrench: a 10 Nm bolt is snug with a short spanner held in the fingers; 25 Nm is a firm pull on a normal spanner; 50–85 Nm is a hard pull on a long one. Small bolts snap long before you feel it: go gently below M6.

Wood screws and nails

  • Screw length: about 2.5 × the thickness of the piece you are fixing. Two-thirds of the screw should be in the back piece.
  • Pilot hole in the back piece: the diameter of the screw's core (without thread) in hardwood; half that, or none, in softwood. Clearance hole in the front piece: the full shank diameter, so the screw pulls the pieces together.
  • Near the end of a board, always drill first or it splits.
  • Nails: 2.5–3 × the thickness of the top piece. Nail thin into thick. Angle pairs of nails towards each other (dovetail nailing) for grip. Blunt the tip with a hammer tap to stop splitting.
  • Outdoors use galvanised or stainless fasteners; plain steel rusts out in a few years and stains oak.

Seized and stripped

  1. Right tool, straight on

    Six-point socket or ring spanner, not an open-end or adjustable, on a rounded or tight nut.

  2. Penetrating oil and time

    Soak, wait an hour or overnight, repeat. Diesel or a mix of automatic transmission fluid and acetone works too.

  3. Shock

    Tap the bolt head sharply with a hammer, or use an impact driver. Try tightening a fraction first, then loosen.

  4. Heat

    Heat the nut (not the bolt) with a torch so it expands. Never near fuel lines, brake lines, rubber or plastic.

  5. Stripped screw head

    Rubber band between bit and head, a bigger bit hammered in, or cut a slot with a hacksaw and use a flat blade. Last resort: drill the head off.

3 Edge

Sharpening: a sharp tool is a safe tool

Blunt tools slip, need force and cause the worst cuts. Ten minutes on a stone makes an axe, knife or chisel work twice as fast.

Sharpen a knife on a whetstone

stone, coarse side up soak or wet the stone 20° set the angle two coins under the spine ≈ 20° edge-first strokes heel to tip, same angle, 10–20 per side burr feel for a burr on the other side flip, repeat, then finer grit lighter strokes, alternate sides, strop
  1. Soak water stones 10 minutes (splash-and-go stones just wet). Oil stones get a few drops of thin oil. Stone on a damp cloth so it does not slide.
  2. Hold the edge on the stone at a fixed angle. Colour the bevel with a marker: if the stroke removes all the ink, the angle is right.
  3. Push the edge forward as if slicing a thin layer off the stone, sweeping from heel to tip. Keep the angle steady; that matters more than pressure.
  4. Keep going until you feel a tiny rough lip (burr) along the whole opposite side with your thumb, moving from spine to edge, never along it.
  5. Do the other side until the burr flips. Move to a finer stone, lighter strokes, alternating. Strop on leather or cardboard, edge trailing, to remove the burr.
ToolAngle per sideHow
Kitchen knife15–20°Whetstone 1000 then 3000–6000. Hone on a steel between sharpenings.
Outdoor / bushcraft knife20–25°Tougher edge for wood. Scandi grinds: lay the whole bevel flat on the stone.
Axe, hatchet25–30°File coarse, then a round puck stone in circles. Slightly convex edge, no hollow.
Chisel, plane iron25° bevel + 30° micro-bevelFlatten the back first. A guide holds the angle.
Scythevery thinPeen (hammer thin) once a season, hone with a stone every 10–15 minutes of mowing.
Spade, hoe, mower blade30–45°File the top side only. Sharp spades dig twice as easily.
Scissors, shearskeep the factory bevelStone the bevel only, never the flat inner faces. Tighten the pivot.
Sawsby toothTriangular saw file, same strokes on every tooth; re-set teeth with a saw set when it binds.
Grits

120–400: repair chips, reshape. 800–1500: general sharpening. 3000–8000: polish and refine. Without stones: the unglazed ring under a ceramic mug, a smooth river stone, fine sandpaper on glass, or the top edge of a car window.

Chainsaw chains

A sharp chain throws chips; a blunt one makes dust and needs pushing. Round file of the chain's size (4.0, 4.8 or 5.5 mm) in a guide, held at the angle marked on the tooth (usually 30°), 3–5 strokes per tooth, same count on each. File the depth gauges down with a flat file every 3–5 sharpenings. Hitting soil or stones blunts a chain instantly.

4 Build

Woodwork: simple joints that hold

Most survival building is boxes, frames and fences. Accurate measuring and square cuts matter more than fancy joints.

Measure and mark

Measure twice, cut once. Mark with a pencil or knife line and a square; cut on the waste side of the line. Check squareness of a frame by measuring both diagonals: equal = square.

Sawing

Start with a few pull strokes at a low angle, thumb guiding the blade. Then long, relaxed strokes; let the saw do the work. Support both sides of the cut so it does not pinch or tear.

Butt joint + screws

Fast and good enough for boxes and frames. Add glue and a corner block or a metal bracket for strength.

Lap joint

Cut half the thickness out of both pieces where they cross; glue and screw or peg. Strong frames with hand tools.

Mortise and tenon

A tongue fits a slot; locked with a wooden peg through a drilled hole. Needs no metal and lasts centuries: gates, tables, timber frames.

Green wood

Freshly cut wood is soft and easy with an axe, drawknife and auger. Dry tenons go into green mortises: the wood shrinks and grips. Split along the grain with a froe or wedges for strong straight parts.

Triangles do not rack: add a diagonal brace to any rectangular frame, gate or shelf. Wood outdoors lasts much longer with feet off the soil (stones, gravel), a roof overhang and ends sealed with oil or paint. Oak, larch, sweet chestnut and black locust resist rot without treatment.

5 Shape

Metalwork: cut, drill, harden, join

With a vice, hacksaw, files and a drill you can make brackets, hinges, hooks, knives and replacement parts from scrap.

  1. Hacksaw

    Teeth point away from you; it cuts on the push. At least three teeth in the metal: 32 TPI for sheet and thin tube, 18–24 for general use. Slow full-length strokes, about one per second.

  2. Files

    Also cut on the push only. Lift on the return. Clean clogged teeth with a wire brush or file card. Never use a file without a handle: the tang goes into your palm.

  3. Drilling metal

    Centre-punch first, drill a 3 mm pilot, then the full size. Slow speed, firm pressure, a drop of oil. Blue chips or smoke mean too fast. Clamp the work; a spinning sheet cuts like a blade.

  4. Threads

    Drill the tap drill size (table), tap with oil, half a turn in, a quarter back to break the chip. Dies cut threads on rod the same way.

  5. Bending

    Clamp in the vice at the line, bend with a hammer near the jaws. Thick steel bends cleanly when heated to red. Aluminium cracks if bent too sharply; heat helps it too.

  6. Rivets

    Pop rivets need a rivet gun; solid rivets only a hammer: hole, rivet through, support the head, hammer the tail into a dome. Copper wire makes good small rivets.

Hardening and tempering steel

Only high-carbon steel can be hardened: files, springs (car coil and leaf springs), old saw blades, bearing races, chisels, farrier's rasps. Mild steel (angle iron, sheet, most bolts, nails, rebar) stays soft. Spark test on a grinder: carbon steel throws bright, bushy, branching sparks; mild steel gives long straight streaks with few bursts.

  1. Anneal (soften) to work it

    Heat to glowing red in a charcoal fire (fire), then let it cool as slowly as possible buried in ash. Now it can be filed, drilled and shaped.

  2. Harden

    Heat evenly until a magnet no longer sticks (around 770 °C, cherry red), a little more, then quench edge-first in warm oil (vegetable oil at about 50 °C). A file should now skate off it. Water quench is harsher and often cracks the steel.

  3. Temper right away

    Hardened steel is glass-brittle. Polish a patch so you can see bare metal, then reheat gently, in a kitchen oven for 1 hour twice, or on a hot plate, watching the colours below. Quench when the right colour reaches the edge.

Colour on bright steelTemperatureUse for
Pale straw≈ 220 °CScrapers, razors, files, engraving tools: hardest
Dark straw≈ 240 °CKnives, wood chisels, plane irons
Brown / bronze≈ 255 °CAxes, punches, drills for wood
Purple≈ 270 °CCold chisels, hammer faces, froes
Blue≈ 300 °CSprings, saws, anything that must flex: toughest

Soldering

  • Clean both parts bright; twist or hook wires together first so the joint is mechanical. Solder is glue, not a clamp.
  • Heat the joint with the iron tip, feed solder into the joint (not onto the iron). It should flow and look shiny and smooth, like a small volcano, in 2–4 seconds.
  • Rosin-core electronics solder for wires and circuit boards; iron 330–370 °C. A gas iron or a 12 V iron works off-grid.
  • Slip heat-shrink or tape over the wire before soldering. Keep leaded solder away from food and wash hands after.
  • Plumbing and sheet: heavier solder and a flame. Brazing with brass rod and flux at red heat joins steel strongly without a welder.

6 Motors

Small engines: fuel, air, spark, compression

Chainsaws, generators, pumps, tillers and mopeds all work the same way. If one will not start, one of four things is missing.

How a four-stroke engine works

intakeexhaust 1 intakepiston down,fuel-air mix in 2 compressionboth valves shut,mix squeezed 3 powerspark, burn,piston pushed down 4 exhaustpiston up,burnt gas out crankshaft: two turns per cycle
  1. Intake: the piston moves down, the intake valve opens and fuel-air mixture is sucked in.
  2. Compression: both valves close and the piston squeezes the mixture.
  3. Power: the spark plug fires, the mixture burns and pushes the piston down. This is the only stroke that makes power.
  4. Exhaust: the exhaust valve opens and the piston pushes the burnt gas out.
SymptomCheckFix
Will not start, no fuel smell at plugFuel tap on, fresh fuel, fuel filter, chokeDrain old fuel, clean carburettor bowl and jets with thin wire and carb cleaner
Will not start, plug wetFloodedChoke off, throttle open, dry the plug, pull 5–10 times
No sparkRemove plug, reconnect lead, rest it on metal, pull: blue spark?Clean or replace plug, set gap (usually 0.6–0.8 mm), check kill switch and oil-level sensor
Starts then diesAir filter, fuel cap vent, partly blocked jetClean filter (foam: wash, oil lightly), clear the vent, clean carb
Weak, smokes blueBurning oil: worn rings or overfilledCorrect the oil level; worn engines still run, just keep oil topped up
Weak, black smokeToo rich: dirty air filter, choke onClean filter, open choke
Pull cord easy, no resistanceNo compressionValves or rings: bigger repair

Four-stroke

Oil in the crankcase, plain petrol in the tank. Generators, mowers, pumps. Change oil every 25–50 hours; check level before every use.

Two-stroke

Oil mixed into the fuel. Chainsaws, brush cutters, old mopeds. Usually 50:1 = 20 ml oil per litre; older engines 25:1 = 40 ml per litre. Never run on plain petrol: the engine seizes in minutes.

Storing an engine

Run the carburettor dry or drain it, a teaspoon of oil into the cylinder through the plug hole, pull slowly to compression so the valves close. Store dry.

Fuel storage

FuelKeeps (sealed, cool, dark)Notes
Petrol (E5)3–6 monthsWith fuel stabiliser 1–2 years. Stale petrol varnishes carburettors.
Petrol (E10)2–3 monthsEthanol absorbs water and separates. Avoid for storage.
Alkylate petrol (Aspen etc.)5+ yearsExpensive, ideal for chainsaws and generators kept for emergencies. Available pre-mixed for two-strokes.
Diesel1 year or moreWater and "diesel bug" (microbes) are the enemy: full tanks, biocide, drain water from the bottom.
Paraffin / kerosene, lamp oilYearsLamps and heaters. Store in marked cans so no one confuses it with petrol.
Propane / butane bottlesIndefinitelyAs long as the bottle and valve are sound. Butane does not vaporise below about 0 °C.
Danger

Store fuel outdoors or in a detached shed, never in the house, in approved cans with tight caps, away from ignition and children. Rotate stock: use the oldest and refill. Fuel vapour travels along the ground to a pilot flame.

7 Move

Bicycles: transport you can keep running

A bike with a trailer carries 50 kg at three times walking speed on no fuel. Every part can be repaired with a few tools.

  1. Find the hole

    Remove the wheel, lever the tyre off one side, pull out the tube. Pump it up and listen, or pass it through water and watch for bubbles. Note where it was, then feel inside the tyre for the thorn or glass.

  2. Roughen and glue

    Sand the area around the hole, spread a thin layer of rubber cement wider than the patch, and wait until it is dry to the touch (3–5 minutes). This is the step people rush.

  3. Patch and press

    Press the patch on hard from the centre outwards for a minute. Leave the backing film on.

  4. Refit

    A little air in the tube, tuck it in, push the tyre bead back by hand starting at the valve. Check the tube is not pinched, then pump to the pressure on the tyre wall.

Chain

Wipe and oil every 2–3 weeks of use, a drop per link, wipe off the excess. Replace when stretched: 12 links should measure 30.5 cm; at 30.8 cm it is worn and will wear out the cogs. Keep a chain tool and spare quick links.

Brakes

Pads worn to the grooves: replace. Rim brakes: pads touch the rim flat, front edge slightly first. Cables that fray or stick: replace and grease.

Spares to keep

Tubes and patch kits, tyres, chain and quick links, brake pads, inner cables, spokes, bearings and grease, a pump, tyre levers, a multitool with a chain breaker.

8 Fix

Repair and make do: glue, tape, wire and thread

Most broken things can be made to work again with the right glue or a bit of wire. Keep a repair box and use it.

GlueGood forNotes
PVA wood glueWood, paper, cardJoint stronger than the wood if clamped. D3 grade survives damp. Freezing ruins the bottle.
Two-part epoxyMetal, stone, ceramic, gap filling, most plasticsMix exactly, roughen surfaces. Epoxy putty sticks can plug leaks in pipes and tanks.
Superglue (cyanoacrylate)Small hard parts, rubber, closing small skin splitsBrittle, weak in water. Bonds skin instantly.
Polyurethane glueOutdoor wood, mixed materialsFoams and expands; needs moisture and clamping.
Contact cementRubber, leather, shoes, tube patchesCoat both sides, let dry, then press together once.
Silicone, sealantSealing water, glazingNot structural. Sanitary silicone for wet places.
Pine pitch glue (homemade)Hafting blades, waterproofing, arrow headsMelt 2 parts pine resin, add 1 part crushed charcoal and a little beeswax or fine dried dung. Apply hot; sets hard when cold.
Hide glue (homemade)Woodwork, bows, sizingSimmer skin scraps and sinew for hours, strain, reduce. Reversible with heat and water.

Wire

Soft steel "baling" wire and copper wire bind, hang, splint and patch. Twist tight with pliers. A hose clamp repairs a split tool handle, hose or pipe.

Tape and ties

Duct tape seals, patches and bandages gear for months. Self-amalgamating tape seals hoses and wires permanently. Zip ties are fast but go brittle in sun.

Sewing

Back-stitch for strength, whip-stitch for edges. Patch holes from the inside, overlapping 2 cm. A sewing awl with waxed thread repairs boots, packs, harnesses and tarps.

Handles

Ash, hickory or oak, grain running along the handle. Fit a new axe handle tight into the head and drive in a wooden wedge plus a steel wedge across. Soak a loose head only as a stopgap.

9 Stock

Spare parts: what wears out first

The tools last; the consumables do not. Stock the parts that wear, fail or get lost, for every machine you depend on.

Consumables to stock

Manuals

For every engine and machine, keep the manual (printed or downloaded) with its part numbers, oil type, plug gap and belt sizes. Write them on the machine with a paint marker too. See the library.

! Stay whole

Workshop safety: no hospital, no mistakes

A deep cut or a lost eye was an inconvenience when there were hospitals. Without them it can end your ability to work or kill you.

Eyes

Safety glasses for hammering steel, grinding, chiselling, cutting wire and anything under tension. Metal chips from a struck hammer face fly like bullets.

Cutting

Cut away from your body and hands. Clamp the work instead of holding it. A sharp tool needs less force and slips less.

Axe

Split on a chopping block, feet apart, nobody within two axe lengths. Glance-offs go into shins: kneel for small work.

Chainsaw

Chainsaw trousers, boots, helmet with visor and ear protection. Kickback from the top of the bar tip causes the worst injuries. Never cut above shoulder height or alone.

Grinders

Guard on, both hands, stand out of the plane of the disc. Discs shatter. No loose sleeves, hair or gloves near spinning tools.

Lifting

Back straight, lift with legs, get help for anything over 25 kg. Never work under a vehicle held only by a jack: use stands or blocks.

Wounds

Workshop cuts get dirt and rust in them. Clean every wound thoroughly with clean water and keep tetanus vaccination up to date now, while you can (medical). Keep a first-aid kit on the workshop wall.