Wednesday, September 22, 2010

First firing

The weather has been unrelentingly cold and wet for the past three weeks. So the cob oven hasn't exactly dried out. The outer layer of the south-facing wall is partly dry: you can see the lighter colour in the right of this photo. But the rest of the outside, and all of the inside, is still damp. Not really wet, just not dry. And as fall settles in and the weather continues to cool down, I'm not hopefully that the oven will dry slowly and naturally.

It will probably crack a bit as it dries, and that cracking should ideally happen before we put on the last layer, so that we can cover and fill the cracks with it. And I'd love to get the last layer done this fall rather than next spring. Not essential, but I'm hankering for a sense of completeness.

So today we decided to fire the oven for a short time to speed the drying from the inside. We laid a fire inside and watched to see how much smoke there would be and where it would travel. At first there was lots and it blew straight at the kitchen door. But then as the fire heated up there was less, and it mostly blew up and over the house.

The spiders were amazing. There were hundreds of long-legged ones in residence on the outside of the dome. I suppose they like the texture. They got all excited when we made the fire, just from the activity of humans nearby, but they couldn't really figure out what to do. So for a while the dome was host to a milling crowd of excited arachnids. I don't mind spiders in the slightest, so I was quite entranced by the spider rave.

So far the dome hasn't exploded into dozens of super-heated fragments of hardened clay. Which is nice.

I'm currently looking for an old pre-digital-age TV satellite dish, a 6-foot diameter one. My plan is to use it to build a roof over the oven, mounting it dome up on vertical posts and then planting it with a living roof. All the pictures I've seen of lean-to or peaked roofs look completely incongruous with the round, organic shape of cob ovens. I think a round, grass-covered roof will look nicely hobbit-like.


  1. wow i love the idea for a roof! been wondering what sort of roof you had planned. i hope you find your satellite dish and post lots of pictures!

  2. Anonymous5:27 p.m.

    hey...bug already said it! Great roof idea... and the arachnirave!


  3. Anonymous1:44 p.m.

    Hi Miranda,

    It is great the oven you built. As I look to it now, I remember my parents' oven: in Transylvania.

    It always had a small whole at the rear end, such that was cut out while the whole mud thing was soft. It was just about the size of a fist. This was burned and hardened, but made sure that it would come out when the fire was going on. This was also used to let cold air in if the oven was overheated.

    I do not believe that yours is still soft enough to make such an operation, without damaging the whole.

    That hole helped the oven to have less smoke at the front.

    I long to build one myself.


  4. That sounds like a perfect idea for the roof!

  5. Sara, the second firing was hotter and smoke wasn't really a problem, thank goodness. We had read a lot about door height, chimneys and damper inlets and decided that our basic design would be fine. Happy to be vindicated once we got a really hot fire going ... because it wouldn't have been easy to cut an intake into the dome at this point!


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