Tuesday, May 31, 2011

Finishing the pizza oven

I did it. Today my little helper (hinderer?) and I cut open the oven and removed the sand from the inside of the cob oven. It wasn't drying out, but I am hoping that now it can dry from two sides. We also lit a small fire inside just to hurry things along.

Small opening to scoop the sand out

Sure is dark inside there...

Ah, the interior lit up
The first fire- just a small one to start it drying.

Now I just have to clean up that doorway, and make a nice little door to hold the heat inside as it bakes. I think I will get an old sponge and polish it up a bit more as well. Ummm.... can't wait for the pizza!

Monday, May 23, 2011

Oven and Rice update

Cob pizza oven during polishing process. Kind of looks like my dad's head....
Well the oven has dried enough for me to polish it up a bit. It now doesn't look quite as rough as it did yesterday. The polishing was simple. I took a plastic wrapper- I think that it was an old potato chip bag- put it on my hand like a glove, and smoothed out the dome. The best way was to rub it in circles, like waxing a car. Now it is much, much smoother.

The paddy on its second morning.
The flat of rice seedlings.
A three blade clump of rice to be planted

The rice paddy is doing well- I think. Having never done this before, I am not so sure. But it looks OK to me so far. I lowered the water level slightly since a few seedlings were completely underwater when I checked on it this morning.

Sunday, May 22, 2011

Cob Pizza and Bread Oven

I have been dreaming of this project for years now. And I finally got a chance to do it this year.
I started hauling rocks up from the bottom field last winter. I laid them out in a meter wide circle, tried to make them fit, tore them down and did it again. Then the earthquake came and everything was on hold. But my neighbor decided to let his friends dispose of their earthquake damaged tuff wall blocks on a corner of his property. I thought- wow, those would work really well to make a base for my oven...
At first, I tried using them the way they were, with jagged broken ends and all. But my neighbor's friend gave me the idea to cut the stone into rectangular blocks. I didn't even think about cutting the blocks before, but tuff is basically just a solidified volcanic ash. You can scratch it with your fingernail (but it hurts). So out came the disc grinder with a diamond blade. It cuts tuff like a hot knife through butter. But the problem with a grinder is, it only cuts about 25mm deep. But this gave me the excuse to buy a cold chisel and a rock hammer! Woo Hoo! Put them in the slot made by the grinder, tap it a few times, and off it comes, pretty as could be. Soon I had a base about 60cm tall. It is a pretty good working height. Low enough to be stable, and high enough to work without laying down on the ground to see inside.

Next, I filled the cracks with sand, and laid a 2cm thick bed of sand over the top of the base. Then I laid red bricks on the sand, dry fitting them tightly. This will be the floor of the oven.

Then, I made a sand castle (well, it looked like Homer Simpson's forehead actually) on top of the bricks with my daughter's help. It collapsed a few times, but we finally came up with the solution of having the hose dribble into a saucer shaped depression at the top while we worked. That kept the sand moist enough to hold its shape. Before the sand castle could dry out, we covered it with a plastic bag. This sand dome is just to hold up the cob we will build around it. After it has dried a little, we will remove the sand through the door to create the void inside.

That was when the really fun part started. We pitched three buckets of sandy clay onto a blue tarp, watered it, and began to dance on it barefoot. The clay stuck to our feet, squeezed between our toes, and splashed up onto our clothes. It was great fun. When the consistency was just right- kind of like warm modeling clay, we began to make 8-10 cm balls of it and slapped them around the plastic covered sand dome. It took three mixings of cob to completely cover the dome. This layer of cob is dense- no straw in it- so it can absorb a lot of heat when we fire it. I poked a lot of shallow dents in it with my fingers so the next layer would have something to grab on to.

Now we went back to the tarp- three more buckets of clay soil and a bit more water than before, and we had cob with the consistency of toothpaste. Then we added a five gallon bucket of rice hulls and mashed them in. The rice hulls add a lot of volume, and drastically reduce the density of the cob, while increasing the tensile strength. We slathered this over the dome as well, about 10 cm thick. This is the insulation for the dome.
Anybody can help make cob!

 And finally, the finishing layer. We mixed up yet another batch of cob. The boy made it rather thin by adding too much water. But that is OK. Then we added some cattail fluff to the mix and stomped it in. Hopefully the fluff will give the clay enough tensile strength to keep from cracking. We then frosted the rice hull cob dome with about 2 cm of the cattail fluff cob. Later, when it dries out just a bit, we will polish it up with some smooth plastic until it is smooth as silk.

Last year's cattails look pretty shaggy.
Let it dry and I'll cut the door out soon.
Now the only thing left is to keep it covered until the rain lets up, and then cut out the door. Doors should be as wide as whatever pan you intend on using in the oven, and 60% of the height of the interior. Our sand dome was 50cm high, so the door will be 30cm. After I cut out the door, I will have to remove the sand and the plastic bag that covered it. I am really looking forward to that!

Rice Planting Time

Saturday was the big day. The neighbor had planted his rice the day before, and gave us some of the leftover flats of seedlings he had left. So we started the big day.

Step One: used the brush cutter to slash down all the weeds growing around the paddy. Mostly just for aesthetics, but also to make sure there were no snakes hiding out on the banks.

Step Two: Used my kuwa (a Japanese hoe) to stir up the bottom and loosen the paddy. Also it was to chop up some of the field horsetail that thrives where I built the paddy. After chopping and loosening, I was able to use the rake and take out a lot of the root systems. At least I hope so...

Step Three: We all took our shoes off and got into the paddy. Inside, I stretched a nylon string attached to two stakes across the paddy. This was our planting line. I broke off pieces of the rice seedlings and handed them to the kids, and we started to plant. Every 15cm we planted three or four blade bunches. The paddy soil was mostly sand, so it was hard to push the seedlings in, but we managed.

Bunches of 3-4 rice seedlings at 15cm spacing.
The middle child loves planting
At about the halfway point, the youngest got too bored to continue, so we decided to leave off there for the time being. Later, when I went out to take the goats up to the house, I finished the job.
Finished! You can see the flat of seedlings in the corner on the paddy bank.