Information from the archives of the Warm Glass website and bulletin board.

Kiln Shelves for Large Kilns

Since the largest mullite kiln shelves commonly available are approximately 2 feet by 2 feet (61cm by 61cm), larger kilns are often outfitted with several kiln shelves, rather than one large shelf.  This arrangement works well when fusing smaller items, but the seams between the shelves make it difficult (if not impossible) to successfully and cleanly fuse items that are larger than the individual kiln shelves.  As a result, a number of different solutions to the large kiln shelf problem have been attempted.  Here's a list of possibilities:

Hiding the seams:

1. Fiber paper over the shelves

2. Refractory paste to fill in seams

3. Refractory scraps to cover seams (and add texture)

Alternative shelf materials:

1. Fiber board, vermiculite board, similar products in stock sizes (typically 2 feet by 3 feet/61cm by 91 cm)

2. Custom sizes of fiber board and similar products

3. Rigidized fiber blanket

4. Moldable papers and boards (i.e., Zircar's RS100 board)

5. Stainless steel

6. Castable refractories

7. Leveled sand

8. Plaster/diatomeacous earth/vermiculite/alumina mixtures

As you would expect, some of these alternatives work fairly well, while others come with a different set of problems.  Click here to go to the next part of this series, which deals with solutions that hide the seams between kiln shelves in the larger kiln.

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Copyright 2006 Brad Walker.  All rights reserved.

Most of these tips came from posters on the Warm Glass bulletin board.