Loading a kiln for glaze firing requires more care than bisque firing. Proper preparation and careful placement can help achieve consistent results, prevent damage, and extend the life of your ceramic kiln.
1. Handle Light Glazes First
Load light-colored glazed ware first and keep a clean cloth nearby to wipe your hands, especially after handling dark glazes. This helps prevent glaze cross-contamination and unwanted color transfer.
2. Clean and Prepare Kiln Shelves
Check kiln shelves for old glaze drips before loading. Remove any residue with a chisel or sharpening stone, then repair the area with kiln wash if needed.
Wipe away dust and debris before use, and make sure the shelves are clean to prevent particles from falling onto your work.
3. Build a Stable Shelf Stack
Position kiln posts in a stable triangular arrangement to distribute weight evenly. Keep the lowest shelf about 1 inch above the kiln floor to promote good heat circulation.
Take care when loading shelves to avoid damaging the thermocouple.
4. Leave Space Between Glazed Pieces
Never allow glazed pieces to touch or overlap. Leave enough space between each piece to prevent contact during firing.
Glaze firing generally requires more space than bisque firing, so careful kiln loading is essential.
5. Use Pyrometric Cones
Place pyrometric cones inside the kiln to monitor actual heatwork. Position them around the middle of the kiln chamber, and use more than two locations when possible to check heat distribution.
6. Stack Shelves Carefully
Place each set of kiln posts directly above the posts below to maintain a stable, balanced stack. Lower shelves carefully to avoid hitting the refractory bricks.
Leave at least 1 inch of clearance between the top of the ware and the kiln lid, then close the lid slowly to prevent dust or debris from falling onto glazed surfaces.
7. Keep a Kiln Log
After firing, you may hear occasional pinging sounds as the glaze and clay body cool and contract. This is generally normal.
Keep a kiln log for every firing, recording the load, glaze, temperature, firing schedule, duration, and any unusual results. These records will help you fine-tune future firings and achieve more consistent results.
Final Thoughts
A successful glaze firing starts with careful kiln loading. Clean shelves, proper spacing, stable stacking, and accurate heatwork monitoring all help produce better results while protecting your kiln and your work.