Stacking an electric kiln properly is essential for successful firing results and kiln longevity. It involves carefully arranging shelving and pottery ware to ensure even heat distribution and prevent damage.
Getting Started
Before you begin stacking, ensure your kiln shelves are coated with kiln wash. This prevents glaze drips from sticking to the shelves. Allow the wash to dry completely.
Stacking Shelves and Ware
The process involves building layers of shelves and ware within the kiln chamber.
- Place the First Shelf: Carefully place the first kiln shelf at the bottom of the kiln chamber.
- Set the Bottom Posts: According to best practices, the bottom layer of shelving should be on 1/2" - 1" posts. Select four or more kiln posts of the appropriate height (1/2 inch to 1 inch) and place them on the kiln floor beneath the first shelf, ensuring the shelf is level and adequately supported.
- Arrange Your Ware: Place your pottery pieces directly on this first shelf. Distribute the ware evenly, avoiding overcrowding. Do not allow pieces to touch each kiln element or the side walls.
- Place Posts for the Next Shelf: Posts are set around the perimeter of the first shelf, directly on top of it, to support the subsequent shelf. Use posts of a consistent height across the layer to keep the next shelf level.
- Add the Next Shelf: Carefully lower the next shelf onto the posts.
- Check Clearance: This is a critical step. Make sure you leave at least 1/2" between the top of your tallest piece and the next shelf, to allow for expansion during firing. This clearance prevents pieces from pressing against the shelf above as they expand slightly during the firing cycle, which can cause cracking or damage.
- Repeat the Process: Continue building layers by placing ware on the shelf, setting posts around the perimeter, and adding the next shelf, always ensuring the minimum 1/2" clearance above your tallest ware.
- Stack to the Top: Repeat until you reach the desired height or the top of the kiln chamber, leaving adequate space below the lid elements.
Key Considerations
- Post Alignment: Stack posts directly on top of the posts in the layer below to create stable columns supporting the shelves.
- Weight Distribution: Try to distribute the weight of the ware and shelves evenly across the kiln floor and throughout the stack. Place heavier pieces on lower shelves.
- Airflow: Leave space between pieces on each shelf to allow for proper airflow and even heat circulation.
By following these steps and paying close attention to clearances and post placement, especially the guidance to use 1/2" - 1" posts for the bottom shelf and ensure at least 1/2" space between ware and the shelf above, you can effectively stack your electric kiln for optimal firing results.
