Metal is the soul of a resonant board. A hard, fine‑grained alloy like a bronze with a high tin content will hold a bright, ringing tone. If you want warmth, a low‑silicon steel that’s been tempered and annealed will give a mellow, rich sound. The forging process is what shapes that soul. Begin with a flat slab and hammer it thin. Each strike refines the grain, aligning it and eliminating hidden stresses. The more hammer blows you give, the smoother the grain, and the clearer the vibration. After the final shape, a heat‑treating cycle—heating to a critical point then quenching, followed by a controlled cooling—sets the hardness. A quick heat‑treat keeps the surface stiff for sharp attack; a slower, more gradual temper gives a deeper, sustain‑rich resonance. If you’re building a hammered dulcimer, keep the ribs and bridge plates tight but not over‑tensioned. The bridge should be of a slightly softer metal, like an alloy of copper and tin, to transfer vibrations efficiently. For a brass‑based lyre, use a thin brass plate for the soundboard, and a pair of tension wires that run through small steel bearings to keep the vibration consistent. The thickness of the soundboard is key: thinner is brighter, thicker is warmer. In short, choose your alloy for the desired tone, hammer it to refine grain, treat it to set hardness, and finish it with careful thickness and bridge design. That’s how you forge a resonant surface that sings.

For sustained, dreamy chords I lean toward a bronze with a higher tin content, around twenty‑five percent. That mix gives a longer sustain and a gentle, glass‑like resonance. I keep the plate a bit thicker, so it doesn’t snap back too quickly, and I anneal it carefully to keep the grain smooth. The result is a surface that holds its note like a crystal, letting the chords linger before they fade.

A copper‑tin bridge is a good choice. It’s softer than pure steel, so it won’t clamp the vibration too tightly. That lets the bronze plate vibrate a bit longer, giving you that extra breath of sustain. Just make sure the bridge is well‑matched to the plate’s thickness—too soft and it will wobble, too stiff and it will cut the sound short. Keep the angles clean and the contact points tight, and you’ll get a seamless blend.