So if you’ve been reading this blog from the beginning then you know I started writing it after we began building the oven. You can say we are building with cob, earth, clay or adobe and they’re all true. We began with the idea of just cob but, after looking at my design and getting some hands on experience I found that mixing the different types of construction has great benefits and will be mixing them as this project progresses.
So this project has taken a long time so far. We began collecting rocks and urbanite in July of 2010 and it’s now January 2011. Unfortunately with my injuries I can’t do to much at one time and my kids have school and some are in other states so we really only work on the weekends and vacations. During the summer here in Arizona we could only work outside for an hour or so at a time and during the winter we’ve had a few weeks of freezing temperatures.
So what I’ve learned so far about working with weather is important. In extremely hot weather you have to keep your work damp or it dries to fast and cracks but, damp is not wet and too wet means your work falls apart. With cob you can only do a layer or two at a time and you have to let the cob set before adding more. In the hot weather the cob can set in 5 to 10 minutes but in the cold weather it can take 30 to 45 minutes. You can work in the cold weather but, not if it’s going to freeze. The cob doesn’t set right, it will freeze and expand then be very week and crack. So don’t do any real work if it will freeze before it can dry. So I don’t recommend building in the winter.
I have also learned that the rain is your enemy. If you know or even suspect that it might rain before you get your project done and sealed then get a good tarp is your best friend.
You can see in these pictures where the rain washed some of the cob off and smoothed out a lot of the rough sides. I covered the dome and chimney of the oven but, my tarp wasn’t big enough to cover the base as well and this is what happened. So believe me when I say rain is the enemy.
So this is where we’re at right now with our project. Hopefully by the end of this month the freezing temperatures at night will be over and we can begin the next steps. We need to add the insulative layer, outer layer, repair the base and begin making all of our adobe bricks. Can’t wait to get started again.