Two Kinds of Welding, One Workshop

Most people who take up blacksmithing imagine the hammer and anvil long before they think about welding, yet the join is often the thing that makes a piece possible. A forge-welded scroll, a pair of tongs brazed at the reins, a steel frame that has to hold a gate for thirty years — all of these ask questions that a hammer alone cannot answer.

In a traditional smithy you will meet two distinct methods. Forge welding is the ancient one: you heat two pieces of iron or steel until they are almost white-hot, dust them with flux, and hammer them into one solid mass. Arc welding is the modern arrival: an electric current jumps between an electrode and your work, melting both into a molten pool that fuses as it cools. They are not rivals. They are colleagues, and knowing when to reach for each is what separates a smith who struggles from one who works cleanly.

Safety Before Sparks

Neither method forgives carelessness, and the risks differ enough that you need a routine for each. Before you strike an arc or light the forge, sort out the basics.

• Eyes: a proper welding helmet with the correct shade for the process, plus safety glasses underneath for chipping slag. For forge work, tinted goggles or a face shield stop scale and flux from finding your eyes.
• Skin: leather apron, gauntlets, and no synthetic clothing. Cotton or wool only — polyester melts onto skin and turns a minor burn into a hospital visit.
• Air: forge welding produces fumes from flux and from any coatings on the metal. Work with extraction or in a well-ventilated space, and never weld anything galvanised without serious ventilation and a respirator.
• Fire: keep a clear zone around the anvil and bench, and remember that hot metal looks identical to cold metal. Chalk or paint the ends of anything you have just worked on.
• Electricity: for arc welding, check the earth clamp and lead insulation every session. Damp floors and bare cables are a poor combination.

Forge Welding: Heat, Flux and a Clean Scarf

Forge welding is the technique that built wrought-iron work for two thousand years, and it is still the tidiest way to join pieces that will be hammered, twisted, or left with a fire scale finish. The principle is simple: bring both surfaces to a temperature where the metal becomes plastic and slightly sticky, exclude oxygen with flux, then press or hammer them together so the atoms interlock.

Preparation is everything. Shape the ends into matching scarves — tapered, slightly domed faces that meet across a broad area rather than butting flat end to end. Wire-brush them clean and bring them to a bright orange in the fire together, so they heat at the same rate.

Take them out at a good welding heat — a lemon-yellow that looks almost wet — dust with borax or a commercial flux, and return them to the fire. When they sparkle and the flux runs like glass, bring them to the anvil and set the weld with light, fast hammer blows, working from the centre outwards. Heavy blows at the wrong moment will shear the joint apart.

Forge welding suits wrought iron and low-carbon steels best. High-carbon and alloy steels are fussier about temperature and can crumble under the hammer, so learn on mild steel first.

Arc Welding: Power, Rod and Clean Metal

Arc welding does the jobs that forge welding cannot easily manage: long seams, thicker sections, repairs, and joins where you simply cannot get both pieces into the fire at once. A basic stick welder and a supply of general-purpose rods will handle most light fabrication in a smithy.

Success starts with preparation. Grind or file the joint back to bright metal — mill scale, rust and paint all interfere with the arc. Fit the pieces with a small gap so the weld can penetrate fully, and tack them in place before you run a full bead.

Set your amperage according to the rod diameter and metal thickness; too low and the rod stutters and sticks, too high and you blow holes through the work. Strike the arc by scratching or tapping the rod, hold a steady angle of around fifteen degrees from vertical, and travel at a pace that keeps the molten pool consistent. Let each bead cool, chip the slag with a chipping hammer, and inspect before laying the next pass.

Practice on scrap plate before you touch a finished piece. Flat beads first, then fillets, then vertical and overhead work once your hand is steady.

Choosing the Right Method

Ask yourself three questions. Will the joint be seen? Forge welding leaves a seamless transition with no visible bead, which suits traditional ironwork and pieces that will be finished with wax or oil. Arc welding leaves a bead, which is fine on structural work and can be dressed back if you want it tidy.

How thick and how long is the join? Forge welding favours short, well-fitted scarves; arc welding copes with long seams and heavier sections with less fuss.

What is the metal? Wrought iron and mild steel forge weld beautifully. Alloy and stainless steels are far more predictable under an arc. And if the piece is going to carry load — a bracket, a hinge, a gate frame — an arc weld made properly is easier to trust and inspect.

Build the Skill Slowly

Beginners often try to run before they can walk: complicated scarf joints in the fire before they can hold a steady arc, or a structural weld before they can strike an arc at all. Give yourself a month of simple practice on each. Weld scrap plate flat, chip the slag, and break the joint to see how well it fused. Forge weld short bars of mild steel end to end, then bend them to destruction to see whether the join held or failed.

Both skills reward patience. The fire will tell you when the metal is ready, and the arc will tell you when your travel speed is right — you simply have to learn to listen. Once you can do that, you stop being a person with a welder and start being a smith who can join anything in the shop.