Prepare pieces for salt or soda firing
In salt/soda firing, the "glaze" isn't applied beforehand: it forms in the kiln when salt (NaCl) or soda ash (Na₂CO₃) is introduced at high temperature. The sodium vapor reacts with silica in the clay to form a glass coating.
Preparation
- Apply flashing slips to bisqueware (these interact beautifully with sodium vapor)
- Leave some areas bare clay for contrast (different surfaces respond differently)
- Wax feet heavily (the kiln shelf gets coated too; anything unprotected fuses)
- Make draw rings: small clay rings you can pull from the kiln mid-firing to test salt buildup
Document your slip placement
Sketch or photograph where you applied slip vs. bare clay. After firing, you'll want to correlate placement with results.
What to expect
The characteristic salt/soda surface has an "orange peel" texture: slightly bumpy, like the skin of an orange. It's distinctive and beautiful.