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Hi all, I'm planning on building a hobby kiln for my partner, and am in the process of choosing refractory materials and kanthal wire for the heating element. Was hoping I could get some advice from anybody who knows about these things. I want the kiln to be light weight and very efficient. I'd like to use ceramic fibre board as an inner layer of insulation (rated to 1400 C / 2550 F), and calcium silicate board as a secondary layer (rated to 1000 C / 1830 F). The ceramic fibre board is very expensive compared to the calcium silicate board, but i can't only use the calcium silicate board as it's only rated to 1000 C / 1830 F. So my idea is to cement the two boards together, with the calcium silicate board on the outside, so that it won't exceed 1000 C / 1830 F. I'm wondering how thick the ceramic fibre board needs to be such that the calcium silicate doesn't reach that temperature. We'll be firing the kiln to about 1280 C / 2340 F. My other question is about kanthal wire for the heating elements. I'm wondering what gauge of wire I need. The kiln will be about 40 litres / 1.3 cubic feet. I want it to get up to 1280 C / 2340 F. Based on similar designs that I've seen online, it looks like I'd need it run at about 3600 watts. I'm wondering what gauge kanthal wire I should use for a well-insulated kiln that meets these specs. If anyone has any idea about either of these questions I'd really appreciate your thoughts! P.S. I'm aware of the health risks of working with fibreboard, and will be using the proper PPE and precautions.