Want to continue building an earth oven with the lovely people at
Saffron Acres? (next session Saturday 28th June – are you available?)
LESSBIG is ‘on site’ and needs your help!
Previously, on LESSBIG…
(See Part 1 here)
(See Part 2 here) I like the base, base, base, base
Always happy to see it standing after some more considerable rain and bad weather, even if it was mainly covered up. The mini dome, not covered, is still there.
We cut some pieces of birch for a border. (With a crosscut saw, not a rip saw – thanks Bruce!)
Hooray it’s level! And not very white any more!
The glass layer in there for insulation. I have seen some designs with these placed vertically; you’d need more but it would create a deeper layer. I have seen others without the glass layer too, so who knows?
The bottle layer will be exposed at the rear. Didn’t plan this, but actually it will be nice to show the different layers once it’s complete rather than hide it away entirely.
A brief shower later, the bottles are now buried under a bit more cob. You can see it is easy to get narrower as you get further up. It’s currently about 100cm2 at the base and about 75cm2 on the plinth; this will knock on to affect the size of the oven of course. I’m expecting to be able to get at least a 10in (25cm) bread peel / baking tray through the opening.
A little sand goes on to provide a level surface
Precision stick work, simple but effective!
Partly to make sure it is compressed, as well as to level it
Bricks for the bottom of the oven…or are they? While I picked these up from round the site as they were intact and a good colour, on further research I realize they may in fact be concrete pavers, not actual clay bricks. I may go out and buy some proper firebricks; specific for this kind of application. They are very dense with a high alumina content, so they are a lot tougher (in terms of temperatures) and also are less porous, meaning a hotter, drier oven overall.
With a little rubber mallet and a level, we quickly ‘persuaded’ the bricks into order. A bit of extra sand to fill in gaps, seems to make insulative sense! Not mortared in so easy to remove if need be. That’s where we finished.
Right, let’s chuck the little one on and give it another go, now it’s properly dry!
After 20 mins or so of shoddy newspaper and twig fire, while the dome felt warm, my snazzy new oven thermometer didn’t even twitch (it starts at 60c). It’s just too hard to get a small fire burning consistently so the little one might never really work. I might stick it out in the hedge somewhere, see if a mouse moves in or something. Might make a good bee hotel.
Added to the first session, in terms of time, I would say this is about 38 person-hours so far?
Get in touch (
firstname.lastname@example.org ) if you want to help out with the next stage on the 28th of June, when we will probably be able to finish it off and give it a test fire at least.
For those of you who don’t know where Saffron Acres is, it is fairly central, on Copinger Road, just off Saffron Road. Near the Aylestone Leisure Centre. If you don’t fancy the oven, they’ve got tons of other stuff you could get involved in!