This is a really fun project, but it's also a messy project that needs to be done with care.
When making sand-cast candles, you use packed wet sand to form the mold that will contain the hot wax. That's the process in a nutshell. Now let's go over it in detail.
¥ Old candle stubs and/or paraffin blocks (like those used in home canning)
¥ Broken crayons
¥ Tea lights or short candles (to use for wicks)
¥ Sand (beach sand, playbox sand or colored sand all work well)
¥ Containers about the size of a medium yogurt container (to hold the sand)
¥ Molding objects (such as baby food jars, tiny flower pots or tennis balls)
¥ Double boiler or the equivalent (one that won't be used for cooking again!)
¥ Wooden craft sticks (to stir the melting wax)
¥ Large spoon
¥ Lots of newspaper
¥ Stove or hot plate
¥ Stiff brush, such as an old toothbrush
First, cover all surfaces with several layers of newspaper. Next, decide what kind of sand you will use. You may want to bring home a bucket of sand from the beach (if it's allowed) or take a bucket of sand from your sandbox.
Divide up the sand among several yogurt containers; you'll be making one candle per container. Wet the sand liberally with water and stir it all up with a large spoon, just like you were mixing cake batter. Be sure the sand is wet through and through. Press your molding object – baby food jar, a ball or whatever – into the wet sand. When you lift it out, it will leave a cavity or depression roughly the size and shape of the object.
Now let's make the wick. If you are using a tea light, remove it from its metal cup and place it at the bottom of the sand mold. Be aware that you must make the candle a little shorter than the wick, so a candle made with a tea light wick will of necessity be a short candle. Another alternative is to use the stub of a used candle. You will be able to make a candle that is a bit taller if the stub is, say, two or three inches high. If you are using a stub, stand it up in the bottom of the sand mold.
On to the melted wax. If you don't want to dedicate a double boiler to candle-making, you can rig up a makeshift affair as I did. I used an old cookie tin as the bottom of the "double boiler," and a pot I was ready to discard as the top. Put a small amount of water in the bottom section, place it on the stove or hot plate burner, and set the top section in the water. The wax goes in the top section. I was able to recycle several half-burned candles for the wax. In the past, I have also successfully used paraffin – the kind used in home canning. Coloring the wax is achieved by adding several crayon stubs (paper removed) to the wax. Use a low heat and allow the water to come to a slow boil. The wax will melt rapidly. You can use a wooden craft stick to stir the wax and blend the colors.
Gently, carefully pour the melted wax into the sand mold, being sure the wick remains upright. Allow half an inch of wick to remain above the wax. It will take a while for the wax to harden.
When the wax is hard, you can take the candle out of the sand. Whether tall or short, fat or thin, lumpy or smooth, your candle is sure to be a unique work of art!