Why reclaimed is the smith's traditional approach

Every forge is essentially a hole in the ground with air blown into it. That's not a simplification for beginners — it's the truth of the craft. Forge a fire in a trench in the earth, lay a pipe to it, and you have enough heat to move steel. Everything else is convenience, comfort and control.

Which is why a scrapyard forge is not a compromise. It is the historically honest way to start. A usable solid fuel forge can be assembled for the price of a bag of coke and a few hours' work, using materials that would otherwise go to the tip. What follows is the setup I recommend to anyone starting out in a British back garden or workshop, built around reclaimed brick, a steel pan and a length of pipe.

What you actually need, and what to look for

A forge has four jobs: hold the fuel, feed it air, keep the heat off you and give you somewhere to rest hot metal. Keep those in mind and the shopping list writes itself.

• The firepot: a heavy steel or cast iron pan. A discarded sink, a brake drum, a deep roasting tin with the base reinforced, or half an old gas bottle (never cut a gas bottle without purging it thoroughly first).
• Brick: reclaimed firebricks are the prize — they turn up in old boilers, kilns, Rayburns and demolition skips. Ordinary house brick will do around the outside, but it will crack and spall at the fire face.
• Pipe: 40–50mm black iron or mild steel tube for the tuyere, plus a longer length to bring air in. Never use galvanised pipe. Zinc coating gives off fumes that will make you properly ill.
• Air: a hairdryer on its cool setting, a hand-cranked blower from a boot sale, or a vacuum cleaner on blow — with a bleed hole cut in the pipework so you can throttle it back.
• Lining: fireclay, sharp sand and wood ash, mixed to a stiff, crumbly paste. Cheap, forgiving and easy to repair.

Avoid concrete blocks and any brick containing flint or trapped moisture near the fire. They can spall violently when heated.

Building the firepot and tuyere

Turn your pan upside down and mark a hole slightly off centre, sized to take the tuyere pipe with a snug fit. Cut it, then weld or braze the pipe in place, angled down at roughly 20 to 30 degrees so the air ducks under the fuel rather than blasting straight up the chimney of the fire.

Some smiths run the blast in through the side of the pot instead, a finger's width above the base. Side blast suits deep, narrow fires and is gentler on small work; bottom blast gives a wider, hotter fire. For a first forge, bottom blast is easier to live with.

Fix a T-piece into the inlet line below the pot. One branch goes to your air source, the other stays open with a simple flap or a sliding collar. That open branch is your throttle — cover it and you get full blast, open it and the air takes the easy path. It costs nothing and it is far better than a switch.

Laying out the hearth

Set the pot into a bed of sand on a firm, non-flammable base — a paving slab on bare ground is ideal. Build brick up around it to form a shallow hearth, leaving one side open towards you so you can rake fuel and reach the fire.

The top of the fire should sit roughly at the height of your wrist when standing relaxed, about 850 to 950mm. Too low and your back will complain within a week.

Now line the pot and the inner face of the brick with your clay, sand and ash mix, working it into a bowl shape about 50mm thick. This is the duck's nest, and it does two things: it insulates the fire so it reaches welding heat, and it protects your pan from burning through. Leave it to dry slowly — a day in a warm shed, or a few gentle fires. Blasting a wet lining will crack it.

Pipework, air supply and finishing touches

Run the inlet pipe out to the side of the hearth where your blower will live, away from the smoke. Keep bends gentle — every sharp corner robs you of air. If you are using a vacuum cleaner, fit the bleed valve described above or the fire will look like a rocket test and burn fuel at a ridiculous rate.

Add a flat steel plate or a heavy offcut as a fire back on the far side of the hearth; it reflects heat at your work and stops the brick taking the worst of it. A shallow tray underneath catches ash and makes cleaning out a two-minute job rather than a chore.

First fire, fuel and safety

Start small. Paper, kindling, then a handful of coke or lumpwood charcoal. Bring the blast up gradually — you want a fire you can look into, not one you have to squint past. A good forge fire is a hollow bowl of glowing fuel with a cool-looking dark centre; that dark centre is where the heat actually is, and where your steel belongs.

On fuel: coke is clean, hot and legal anywhere. Bituminous smithing coal gives a lovely coking fire but is banned in many UK smoke control areas, so check before you buy a sack. Charcoal is friendly, sparks less and suits small work well.

Finally, the boring bits that keep you smithing for years. Work outdoors or with serious ventilation — carbon monoxide from a forge is genuinely lethal. Keep a bucket of water and a dry powder extinguisher within reach. Wear eye protection always, and leather boots rather than trainers, because hot scale finds every gap. Then light it, and enjoy the fact that a pile of scrap and a bit of pipe has just become a workshop.