is 2" enough thermal mass?

[mpjfitz]

Hello

The fire-bricks I am using to build the hearth and dome are quite unusual in shape. They measure 9" x 7.5" x 2". They come from night-storage heaters and a cost effective alternative here in the UK. I've been collecting them for over a year so far and they haven't cost me a penny I have plenty, and could build the dome using the 2" side on the internal face of the dome. Yes, that will mean a lot of cutting and many layers, so I wanna avoid that.

My question is: if I use the bricks in such a way that I have a 2" thickness to the walls and hearth. Will that be enough thermal mass to keep the oven hot?

I appreciate the oven will heat up quicker if it's thinner. But I'm not really concerned if I need to leave the fire roaring for longer. I can easily add more thermal mass by rendering the dome. The hearth will be different and I'll need to think that one out

Thanks in advance

Mick

[dmun]

Re: is 2" enough thermal mass?

My dome is two and a quarter inches thick, with no outside rendering, and it works fine.

It's a lot of work to build one that thin, and it's not as strong as a thicker dome, but I don't think it's inherently too thin. After all, that's how thick all the modular ovens are.

I don't think, from experience, that there is any real heat-up time advantage to a thinner oven.

[Neil2]

Re: is 2" enough thermal mass?

4 or 5 inches is more typical. Do you have enough for two layers ?

[mpjfitz]

Re: is 2" enough thermal mass?

If I cut the bricks and use the narrow side (2") on the inner edge I still have enough bricks. That will give me about 4" thickness to the dome. It's gonna take a load more layers/rows and more cutting . But there's no rush