How to Avoid Kiln Shelf Damage?


To avoid kiln shelf damage, follow these guidelines:

1. Proper Kiln Loading:

Ensure that you load your kiln correctly to avoid placing excessive weight or uneven pressure on the shelves. Distribute the weight evenly across the shelf and avoid overloading. Leave enough space between objects to allow for proper airflow and prevent pieces from touching each other.

2. Use Kiln Wash or Shelf Paper:

Apply kiln wash or use shelf paper on your kiln shelves. Kiln wash is a protective coating  contains Kaolin and alumina. When mixing the powder with water make sure it is as thick as milk. Applied to the shelves to prevent glaze drips or melted materials from sticking to the surface.

Shelf paper provides a temporary protective barrier between the shelf and the ceramic object. Both options help prevent direct contact and reduce the chance of damage.

3. Wax Resist:

 When glazing the pottery it is important to make sure there is no glaze on the bottom of the pottery. Glaze can be hard to get off the bottom of the pottery and you end up spending a lot of time trying to get it all off, sometimes it can be missed because the dry glaze may match the color of the bisque ware.

Any area you don’t want glaze to stick to put wax resist on. Just one thin coat will do. The wax makes it much easier to wipe the glaze off the bottom of the pottery. Like water off a duck’s back. Just a few wipes with a clean damp sponge and the bottoms are glaze-free.

3. Clean the Shelves:

Regularly clean your kiln shelves to remove any glaze drips, dust, or debris. Use a soft brush or scraper to gently remove any build-up. This will help maintain a smooth surface and prevent potential damage to the shelves.

4. Avoid Sudden Temperature Changes:

Rapid temperature changes can cause thermal shock, leading to cracks or warping of kiln shelves. Follow the recommended firing and cooling schedules provided by the kiln manufacturer. Gradual temperature changes during heating and cooling cycles are essential to minimize stress on the shelves.

5. Use Kiln Furniture Properly:

Ensure that you are using kiln furniture (posts, stilts, and other supports) appropriately and according to the manufacturer’s guidelines. Place them strategically to provide proper support and stability for your ceramics.

The bottom shelf should be on short posts (1″ high) so that there is at least one inch clearance from the kiln’s bottom slab. This allows heat to circulate under the bottom shelf too, preventing the formation of a cold spot during firing.

Choose thicker posts if you have heavier pieces to fire.

Three posts give more stable footing than four.

Avoid using posts taller than 10 inches if possible.

6. Avoid Direct Contact with Glazes:

When loading glazed pieces onto kiln shelves, be cautious to avoid any direct contact between the glaze and the shelf surface. Glazes can melt and adhere to the shelf, causing damage. Use stilts, posts, or other forms of elevation to keep glazed objects slightly raised off the shelf surface.

7. Handle Shelves Carefully:

When moving or handling kiln shelves, be gentle and avoid banging or dropping them. This can cause cracks or chips that may compromise their structural integrity.

8. Regular Inspections:

Periodically inspect your kiln shelves for any signs of wear, cracks, or damage. If you notice any issues, address them promptly to prevent further damage.

9. Follow Kiln Maintenance Guidelines:

Regularly maintain your kiln according to the manufacturer’s instructions. This includes inspecting and replacing worn-out or damaged kiln furniture, ensuring proper kiln ventilation, and keeping the kiln clean.

By following these guidelines and practicing proper kiln maintenance and loading techniques, you can minimize the risk of kiln shelf damage and prolong the lifespan of your kiln furniture.

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