Sovereignty Module: Fire in the Box
Complete Saggar Firing and Alternative Firing Techniques: From Container to Color
Saggar firing creates unique surface effects by enclosing pots with combustible materials. This campaign covers saggar construction, material selection, pit firing, raku, and horsehair techniques.
Chapter 1: Alternative Firing Methods
| Method | Temperature | Atmosphere | Surface Effect | Difficulty |
|---|---|---|---|---|
| Saggar firing | 1600-1800°F | Reduction (sealed) | Smoke patterns, metallic flashes | Moderate |
| Pit firing | 1200-1600°F | Variable | Smoke marks, earth tones | Low |
| Raku | 1800-1900°F | Reduction (post-fire) | Metallic luster, crackle | Moderate |
| Horsehair | 1200°F (applied hot) | N/A | Carbon lines from hair | Low |
| Obvara | 1600°F (dipped in fermented batter) | N/A | Mottled, organic patterns | Moderate |
| Barrel firing | 1200-1600°F | Variable | Smoke marks, color from salts | Low |
Chapter 2: Saggar Construction
Saggar: a container that encloses the pot during firing. 1) Build saggar from clay (coil or slab method). 2) Saggar must be large enough to hold pot with 2 inches clearance. 3) Walls: 3/8-1/2 inch thick. 4) Lid: flat slab with handle. 5) Fire saggar to bisque before use. 6) Saggar can be reused many times.
| Saggar Type | Material | Reusability | Best For |
|---|---|---|---|
| Clay saggar (coiled) | Stoneware clay + grog | 10-20 firings | Traditional, any kiln |
| Foil saggar | Heavy aluminum foil | Single use | Quick, electric kiln |
| Brick saggar | Firebrick stacked | Unlimited | Large pieces |
| Metal can (improvised) | Steel can or drum | 3-5 firings | Outdoor pit firing |
Chapter 3: Combustible Materials and Effects
| Material | Effect | Color | Application |
|---|---|---|---|
| Sawdust | Smoke marks, carbon trapping | Black, gray | Pack around pot |
| Salt (table or sea) | Orange flashing | Orange, peach | Sprinkle on sawdust |
| Copper carbonate | Green-blue flashing | Green, blue, pink | Sprinkle or wrap in paper |
| Iron oxide (red) | Red-brown marks | Red, brown | Dust on pot or sawdust |
| Banana peel | Dark marks, carbon patterns | Black, brown | Wrap around pot |
| Seaweed | Salt + organic marks | Orange, black | Wrap around pot |
| Steel wool | Iron spots and streaks | Orange, red, brown | Place against pot |
| Copper wire | Green-blue lines | Green, blue | Wrap around pot |
| Newspaper | Smoke patterns | Gray, black | Wrap around pot |
| Horse hair | Fine carbon lines | Black lines | Apply to hot pot |
Chapter 4: Saggar Firing Process
Process: 1) Burnish pot smooth (polish with stone or back of spoon). 2) Bisque fire pot to 1600°F. 3) Sand pot smooth (220-400 grit). 4) Apply terra sigillata (optional, for smooth surface). 5) Line saggar bottom with 1 inch sawdust. 6) Place pot in saggar. 7) Sprinkle salt, copper carbonate, and other materials around pot. 8) Wrap pot with banana peels, seaweed, or copper wire. 9) Pack remaining space with sawdust. 10) Place lid on saggar. 11) Seal lid with clay slip or aluminum foil. 12) Load saggar in kiln. 13) Fire to 1600-1800°F (cone 06 to cone 1). 14) Allow to cool completely before opening. 15) Remove pot, wash gently. 16) Seal with wax or clear spray.
Chapter 5: Raku Firing
Raku process: 1) Glaze bisque-fired pot with raku glaze. 2) Load pot in hot kiln (or heat kiln with pot inside). 3) Fire to 1800-1900°F (glaze melts and becomes glossy). 4) Remove pot from kiln with long tongs (pot is glowing hot). 5) Place pot in reduction chamber (metal can with combustibles). 6) Add newspaper, sawdust, or leaves. 7) Materials ignite from pot heat. 8) Cover chamber (restrict oxygen). 9) Reduction: smoke penetrates crackle in glaze. 10) Unglazed areas turn black from carbon. 11) Metallic lusters develop on glaze surface. 12) After 10-15 minutes, remove pot and quench in water. 13) Clean with steel wool to reveal pattern.
| Raku Effect | Cause | Appearance |
|---|---|---|
| Crackle pattern | Thermal shock cracks glaze | Network of dark lines in glaze |
| Metallic luster | Reduction of metal oxides | Copper, gold, silver sheen |
| Black unglazed areas | Carbon absorption | Matte black body |
| Smoke patterns | Partial reduction | Gray-black patterns on body |
Reference Card
- Saggar firing is controlled chaos (the combustible materials inside the saggar create unpredictable patterns of smoke, flame, and chemical vapor; each firing is unique and unrepeatable). 2. Burnish before saggar firing (a smooth, burnished surface accepts smoke marks and color flashing more evenly; rough surfaces produce muddy, indistinct results). 3. Copper creates the most dramatic colors (copper carbonate produces vivid greens, blues, and pinks depending on temperature and atmosphere; it is the most popular colorant in saggar firing). 4. Salt produces orange flashing (common salt (sodium chloride) vaporizes in the saggar and deposits on the pot surface, creating warm orange and peach tones). 5. Seal the saggar (a well-sealed saggar traps smoke and vapors, creating a strong reducing atmosphere; leaks allow oxygen in and reduce the intensity of effects). 6. Raku is dramatic and immediate (removing a glowing pot from a hot kiln and plunging it into combustibles is one of the most exciting moments in ceramics; the results are visible within minutes). 7. Raku pots are decorative only (the thermal shock of raku firing creates micro-cracks in the clay body; raku pots are not food-safe or waterproof and should be used for display only). 8. Alternative firing connects potter to fire (saggar, pit, and raku firing put the potter in direct contact with the fire; the results are a collaboration between the potter, the materials, and the flames).