Sunday, August 13, 2006
Betong Kurs (Cement Course)
My sister Ann has been making things out of cement for about 6 years now, and is still fascinated with the possibilities. She even has a small business with a friend teaching classes. Jill and I got a short version of the class and each made a flower pot and a stepping stone. We're not sure we had the right kind of concrete mix, and that led to some problems with the decorations, but we did enough to get the general idea.
First you have to mix the dry concrete with the smallest possible amount of water, just enough to get it wet and mixed together. It's like mixing a cake or cookies, just heavier and harder to stir. It should be stirred almost 10 minutes to get a really smooth textured mixture. Cement is caustic, so rubber gloves should be worn and care taken not to inhale the dust or get it in your eyes.
When it's the right consistency, you should be able to form a ball that holds its shape. When you pat the ball flat, you will see a sheen of moisture on it, as water rises to the surface. For the flower pots, we used a plastic food container (with leaves attached around the inside), put about an inch of wet concrete in the bottom, then placed another smaller diameter container inside and filled up the sides. For the stepping stones, we used a larger plastic bucket, and just put an inch of concrete in and let it settle a while before placing leaves on top. In both cases, we had to keep shaking the containers or tapping them on the table to get rid of the air bubbles that are released in the chemical process.
My stepping stone and flower pot. The leaves I used for the sides of the pot just left a very fuzzy image.
My stepping stone. I used 3 hosta leaves on top, after getting most of the bubbles out, and it made a nice pattern.