Insulation necessary around top of the oven?

[jezzaa]

And when wrapping my mould with wet newspaper, presumably I should also wrap the edges of the tiles, so they don't stick to the cast dome?

[david s]

If building a hemispherical oven the internal height should be half the diameter from the top of the floor tiles to the internal crown of the dome. The oven door opening should likewise be 63% of the internal height measured from the top of the floor tiles. If you get a stick cut to the internal height and place it in the centre of the floor you can then easily build your sand castle around it until you reach the top of it.

[david s]

And when wrapping my mould with wet newspaper, presumably I should also wrap the edges of the tiles, so they don't stick to the cast dome?

If building the dome around the floor tiles, most builders like to leave a small gap between the floor tiles and dome to allow for floor tile expansion, so you can use one thickness of corrugated cardboard box to do this.

[jezzaa]

Thanks so much David. Will keep you posted

[jezzaa]

Couple of pictures of progress.... Things seem to be going well!

I have started driving out the moisture and am on my third fire this evening. I can feel some hot spots when moving my hands around the top of the dome. Is this likely because there is a gap in the insulation?

Also, I have bought a flue but, as I did not have it when I cast the hole for the flue, unfortunately my flue does not quite fit in the hole. Is it safe to use a grinder bit on a drill to finesse the hole so the flue sits nicely?

Thanks