Making a candle that cannot be blown out is a fun project for a Halloween party seance, theater work, making special effects for a spooky movie or even as a safe prank. Imagine someone getting a birthday cake and being unable to blow out the candles! Prank candles can be purchased at joke shops, but they are easy and inexpensive to create using some household supplies.
Cut an eight-inch length of the string and set it aside. Various types of string may be used, but cotton core string works well. It is recommended that it be purchased from a professional candle-maker store.
Place a piece of wax or butcher paper on to a flat surface. Take a small piece of magnesium and scrape it on a file to create magnesium dust. Allow it to fall on to the paper and collect the dust into a small pile. About a tablespoon or so will be enough. Magnesium can be purchased at a science supply store or scraped off a piece of pipe from a bicycle.
Melt about 6 to 8 oz. of wax in a pan on the stovetop. It needs to be completely melted into a liquid.
Submerge the cut string into the melted wax in the pan to coat the string in a thin layer of wax. Remove the wax-covered string from the pan and allow it to cool.
Form the magnesium dust into a thin line the length of your string. Roll the wax-covered string into the magnesium dust and coat it well. Press the string down firmly as you roll it, so that the magnesium firmly adheres to the string.
Pour the pan of melted wax into a vertical tube preferable closed on one end. It can be a thin cardboard tube or a professional metal candle mold. Fill the mold nearly to the top. Do not allow the wax to cool.
Dip the magnesium-coated string into the mold of wax and lift it out. Repeat to build the wax up layer by layer until you have a thick candle. Be sure to leave about 1/4 inch of the string sticking out of one end of the candle to act as the candle wick. Alternatively, you can tie one end of the string to a few inch long stick before coating it and after coating it place the wax-covered string into the mold and allow it to dry. The stick holds the string upright until the wax dries. This method requires some expertises from a candle-maker.
Place the candle into a candle holder. Light the wick on fire. Blow the candle out and the string ember will remain glowing, which melts the wax, heats up the magnesium, and re-ignites the flame. It will keep re-igniting each time it is blown out until the candle is all melted and the string is burned away.
To extinguish the flame, dip the burning wick into water to cool the embers. Be careful to place the candle in a safe place because the wick could ignite while unattended.