Packing Without Problems

Dense loading is efficient, but it requires judgment. These principles help you get the most pieces into each firing without creating problems.

Heat Circulation

The kiln needs hot air to circulate around every piece for even firing. If pieces are packed so tightly that no heat can flow between them, some pots will be under-fired while others are over-fired.

• Leave at least a small gap between pieces on the same shelf level.
• Do not block the peep holes with pots; you need to be able to read the cones.
• Keep the area near the elements (in an electric kiln) clear by a few centimetres; too close and local temperatures cause uneven firing.

Weight on Shelves

Each shelf can only support so much weight. Overloading causes shelves to bow and eventually crack.

• Spread weight evenly across the shelf.
• Heavier, thicker pieces go on lower shelves where posts are shorter and more stable.
• Do not stack heavy pieces on top of shelves that are already bowing.

Pieces That Need Special Handling

• Lids: Fire lids on their pots during bisque if they fit. This ensures they shrink identically.
• Handles: Make sure handles on mugs have enough clearance that they do not touch the shelf above.
• Tall thin pieces: Place these near the centre of the shelf or brace them with a small prop; they can tip during firing.

Pro Tip

Sketch a rough loading plan before you start. Work out how many shelf levels you need and where the large pieces go. Loading is much easier when you know where everything is going before you start placing pieces.

Load Balancing Routine

For each shelf level:

• Place heavy forms first
• Fill with medium and small nested ware
• Re-check weight distribution before adding next shelf

Balanced loading reduces warping and shelf stress.

Down the Rabbit Hole

Proper loading ensures even heat distribution, which is critical because clay undergoes sintering during bisque firing, permanently bonding its particles together. Potters often place pyrometric cones at different shelf levels to confirm that every zone in the kiln reached the target temperature.