Afterword & Troubleshooting
Afterword
I am convinced that the technique of mokume gane has a long and glorious future ahead, one to rival its distinguished past. With technical advancements in diffusion-welding processes, and our increased knowledge of metallurgy, the modern metalsmith is optimally positioned to create the highest quality and most exciting mokume in history. Not that technology can ever replace innovative design and true craftsmanship, but rather, technological advances will make things possible for today’s craftsmen of which the artisans of old could only dream. I encourage you to be as bold in your technical explorations as you are with your designs. By pushing the boundaries of our understanding and use of mokume gane, you will help to keep this incredible form of metalworking alive and fresh.
Visually, mokume is powerful stuff! It is magical metal, with a life and power unique in the field of metalwork. It is true alchemy; the transformation of the common into the magnificent, packed with energy and full of references to the natural world around us. We instinctively connect to mokume because of its inherent earthiness, our most basic human aesthetic guides our appreciation and use of this material. Listen for your own inner voice and follow where it leads, whether it dictates sparsity and restraint, or opulence and excess. Mokume has much to offer, use it with wonder and skill, the rewards are many.
Troubleshooting Guide
Metal Problems:
Poor quality ingots or sheet:
• Metal not properly mixed.
• Metal contaminated.
• Metal overheated.
• Mold too hot. (Sunken areas)
• Mold too cold. (Voids & cold seams)
• Ingot not forged enough.
Warped sheet metal or inconsistent thickness:
• Mill rollers not parallel.
• Metal rolled diagonally.
• Over-sanding or over-cleaning.
Firing Problems:
Metal bonds unevenly:
• Uneven firing temperature.
• Metal stack cleaned unevenly.
Billet fuses to torque (clamp) plates:
• Billet over-fired.
• Not enough mica; yellow ochre, or other barrier coating.
Billet metals turn black or develop crusty buildup on edges:
• Improper firing atmosphere.
Billet stack slumped or twisted:
• Over-fired.
• Stack accidentally shifted during eutectic phase.
• Metal shifted when clamping.
Billet not properly laminated:
• Under-fired.
• Uneven firing.
• Billet sheets oxidized or contaminated.
• Sheet surfaces uneven.
• Not clamped tightly enough.
Rolling Problems:
Cracks in edges:
• Reducing thickness too quickly.
• Poor quality or inappropriate metal.
• Incompatible metal hardness.
• Edges of sheet not making full contact with rollers.
• Under-annealed.
• Billet not forged enough.
• No solder covering edges.
Zigzag cracks across surface:
• Poor quality or inappropriate metal.
• Billet curl flattened too abruptly.
• Over-annealing, causing excessive grain growth.
• Incompatible metals in billet.
• Billet not forged enough.
Mokume sheet curls:
• Uneven roller speed or diameter.
• Uneven metal hardness.
Internal layers cracking:
• Poor-quality metal.
• Incompatible metals in billet.
Delamination:
• Under-fired.
• Metal oxidized.
• Contaminates between layers.
• Incompatible metals.
• Reducing thickness too quickly.
Problems with Finished Sheet:
Blisters and bubbles:
• Contaminants trapped between layers.
Layers in finished sheet not proportional to original layer thicknesses:
• Overfired.
• Held at diffusion temperature too long.
• Layers etched away by acid texturing.
Layers ragged, not smoothly defined:
• Incompatible metal hardness.
• Poor-quality sheet metal used.
• Metal grain structure too large from not enough forging and rolling, or over annealing.
Layers muddied or gone:
• Fired too high, or too long.
• Laminate rolled too thin.
• Contaminated acid has plated over layers.
Holes or cracks in finished sheet:
• Pattern punched too deeply.
• Improper gouge contours.
Finished mokume will not accept patina:
• Metals depletion gilded by repeated pickling.
• Contaminated acid has plated over layers.
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