Drawing with chalk on the sidewalk and driveway is very different from creating on paper or a chalkboard. Working in this way allows you to draw really big, and it's fun to create outside with the birds chirping and the sun shining down on your masterpiece! It's possible to make your own chalk by reusing some common materials, which will help save natural resources and landfill space.
|You'll need an extra pair of hands for this somewhat messy project, so ask an adult to mix the plaster for you. Cover your work area with newspapers. Line the toilet paper tubes with wax paper to help release the chalk when it's dry. Seal one end of the tube with duct tape, and stand it on end with the taped side down. Place it inside a box to catch spills. Fill a large, plastic container, such as a an ice cream carton or whipped topping tub, about one third of the way with cool water.|
|Sift plaster of Paris through your fingers, sprinkling it into the water. Keep adding the material in this way, until it stands above the water in dry peaks or little mounds. This will take awhile, because the plaster will keep sinking. In order for the plaster to mix properly with the water, however, it's important to add the right amount.|
|When you reach this stage, you can mix the two together with your hand. Stir the mixture gently, and squeeze out any lumps that may occur. As soon as the plaster is mixed to a smooth, creamy consistency and covers your hand, add liquid tempera until you get the desired color, and mix well with the plastic spoon.|
|Now pour the plaster into the cardboard tube. Depending on how much you mixed, you may have enough to fill several tubes. The plaster will begin to harden in just a few minutes, but allow the chalk to set up in the forms for a week. Plaster is dry when it's no longer cool when you touch it. To remove the sticks, peel the tubes, and throw away the cardboard pieces. Now you're ready to create your masterpiece!|
When working with plaster of Paris avoid prolonged contact with bare skin. Rubber gloves would be useful in protecting your hands.
Do not get plaster of Paris in your eyes.
The sidewalk chalk is not recommended for use on chalkboards.
To save money, buy plaster of Paris at a discount store or lumberyard rather than at craft or paint stores. You will need about one, unpacked cup of plaster for each ½ cup of water.
Plastic baggies or plastic from shopping bags can also be used to line the cardboard tubes instead of waxed paper.
If you wish, substitute cardboard gift wrap tubes for the toilet paper tubes. Just cut the tube into five or six-inch lengths.
The basic or primary colors are red, yellow, and blue, and all other colors, except black and white, are made by mixing them.
The following color mixing chart will help you make additional colors. Mix equal amounts of each color to make the secondary colors. They are orange, green, and violet or purple..
|Color Mixing Table|
|First Color||+||Second Color||Results|
The tertiary colors are red-orange, yellow-orange, blue-green, yellow-green, red-violet, and blue-violet. Mix equal amounts of each to make them.
|Tertiary Color Mixing Table|
|First Color||+||Second Color||Results|
Mixing plaster properly takes a little practice. If the mixture is too liquid, it will take a long time to set up, and the finished stick of chalk will be weak. On the other hand, if you add too much plaster of Paris to the water, it will harden very fast, and it will be difficult to use.
Never mix plaster in a metal container, because you'll be unable to remove it or clean the container when the plaster hardens. Also, be very careful about cleaning up after working with the material. Plaster can clog sink drains! Clean your hands by wiping the plaster on a rag or paper towels, and then rinse in a bucket of water. To remove plaster from the mixing container, wait till it dries, and then scrape it into a trash can.
In addition to drawing pictures on the sidewalk, use the chalk to lay out a hop scotch grid or another game. Visit Sidewalk Chalk Fun to learn some new games..
© 2008 Marilyn J. Brackney
Volume 16 No. 1
Return to Toys & Games Page
Select this to choose other toys and games lessons.