Cob oven work

As we do the fun work of staying cool- making juice popsicles, playing the the sprinkler and finally caving and turning on the AC and reading on the couch, we've also been working on the earth oven. I like that this project is a big one that can be done in small steps, and the boys can help with almost all the steps. It's really fun to work with them, they are very interested in the process.

In the last week, we've sifted soil so the clay will mix well with the sand.

Mixed a test batch of cob to test for shrinkage and strength. Our final proportion is 2 parts sand to 1 part clayey subsoil. The resulting cob mix is sandier than I thought it would be, but it is very strong and resists cracking.

Laid a bed of sand, a floor of firebrick and made a sand form for the oven void. This was tricky as the sand had gotten rained on and was very wet. Twice the whole shape collapsed on one side, this was the pickiest part of the project so far. 

Mixed the dry cob ingredients, (Michael took a whole series of photos of Julian and I mixing the cob and Avery looks this gloomy in all of them!-I think he was tired.) After doing this, we stood on and twisted the mixture with our feet to grind together the clay and sand. 

And started building the walls. 

It's been a slow but steady progress, though the humidity in Kentucky is killer right now and that's hindering the cob-drying process. I am going to work on it more this week hopefully finish the first layer of the oven, but I may have to set up some fans or something if we want to be able to cook pizza THIS summer!