Have I got my dome dimensions wrong?

[Byronius Maximus]

Hi,

I'm now progressing pretty well through my build, with the first clay layer drying out nicely. I've run a few fires in it, gradually increasing in size and I'm glad to say (and quite surprised) that I've had no cracks yet, apart from the clay pulling away from the brick arch, which I've now patched up. I'm now starting on the vermiculite layer.

My biggest concern at the moment is whether I've got the dimensions of my dome right. The main reason for my concern is that, although I ran a fire in it for a couple of hours yesterday, it never got particularly hot - warm enough for steam to be coming off the clay but nowhere near hot enough for cooking anything. I deliberately didn't stoek the fire up massively so maybe that is it, but I am worried that the dome is too tall.

Internal diameter of dome is 910mm, internal height 600mm and height of arch is 375mm (near enough 63% of dome height). I fear the dome may be too tall to get good heat retention, or does this just mean I'm going to have to stoke up the fire more and accept that I'll get through more fuel?

Any advice would be appreciated.

Thanks.

[oblertone]

I think you've already answered your question, yes you'll need more fuel than a smaller/lower WFO but it's all in proportion and it won't be a great deal more. As to your other concern, most of the energy is going to driving out the water content of your dome; as the moisture level decreases more energy (heat) will be stored in the fabric to allow extended cooking or high temp stuff like pizza. Patience is a virtue, so small fires increasing in size over at least a week will see things improve, and you'll easily be cooking at the end of that process.

[downunderdave]

If you see visible steam then you're going at it too hard, back off or risk damage.

[Byronius Maximus]

Thanks both. You've put my fears to rest a little oblertone; I may end up regretting the dimensions but it sounds like I should be able to make it work, even if I end up using more fuel.

I will back off with the fires for a little while then and just have to keep my appetite for wood fired pizza even longer!