I have to admit, this was a new one for us. But, we're loving the little egg head garden the kids put together, at a children's fair, a couple of weekends ago. It's made us think more of recycling egg shells. So, when we ran across a recipe for egg shell chalk, on the Web, and then again in one of our library books, we decided to give it a try.
The first step is to wash out the egg shells, to remove any bits of egg. Then, allow them to dry completely. We, of course, were too impatient for that, and so proceeded with slightly damp egg shells, but I'm sure it's better to actually wait until they are dry.
The second step, which the children enjoyed the most, is to smash the egg shells into a fine powder. We found using a clean rock, on concrete, was the best method. You don't have to pound very hard, so the concrete is not in jeopardy.
For each piece of chalk, a spoonful of the egg shell powder is mixed with one teaspoon of very hot water, one teaspoon of flour, and a few drops of food coloring, if desired.
The chalk like paste, is then rolled in a paper towel or napkin, and left to dry for three days (which by the way, leads to a very nice chromatography experiment).
When dry, the napkin needs to be peeled away, before the chalk is used. Some of our napkin stuck to the chalk, but we were able to rub it off on the sidewalk, before we started to draw.
Ours, was a little grainy, but that might be because we didn't pound the eggshell quite fine enough. We were still able to draw with it pretty well. The color is not as intense as the store bought variety. My daughter, and I, drew side by side pictures in pink. Hers, with store bought chalk, is on the right. Mine, with the egg shell chalk, is on the left.
It's not perfect, perhaps, but not too bad for egg shell, flour, and water.
It's great to be a homeschooler.