Introduction: Solar Candles
Candles are ancient. Today candles have largely been replaced by electric lighting yet we still can't seem to get enough of candles. The beauty they provide is unmatched. The flicker of the candle flame in a dark space illuminates and makes sacred.
This tutorial will show how to make beautiful candles using recycled cardboard to make the candle mold and solar energy to melt the candle wax.
Step 1: Materials and Tools
This project utilizes simple hand tools and materials that are either recycled or easily purchased.
Needle nose pliers
Cardboard tube with plastic lid
Recycled tin cans
Transparent plastic bag
Wire twist closure or clothes pin
Making candles is fun, especially when you have a good friend along to help out (Photos 2 & 3).
Candle making is even more satisfying when materials are recycled and the free energy of the Sun is used to melt the wax!
Step 2: Cutting the Cardboard Tube to Length
The first step is to determine the length of the candle. I purchased precut and mounted candle wicks and used the length of the wick as a guide and cut the cardboard tube to the same length as the wick, using a box knife as seen in Photo 1 & 2.
Step 3: Setting Up the Candle Mold
Take the cardboard tube and fit the plastic lid over the top (which is now the bottom of the mold). This forms a simple candle mold to create a pillar candle. Using a paper napkin or small paintbrush, lightly coat the interior of the mold with vegetable oil. You can also purchase a spray can of candle release which is sprayed on the interior of the mold.
As seen in Photo 1, the mold is placed upright and the wick is inserted into the center of the candle once the melted wax is ready to pour.
Step 4: Making the Solar Melting Pot
It takes two tin cans to make the metal solar melting pot. The cans can be any size that is required for the project. Bigger cans hold more wax and make the melting time shorter. Bigger cans might be more advantageous when making single-colored candles or when making multiple candles at the same time.
One can is shorter and slightly greater in diameter than the taller can so that it fits over the taller can as a lid as seen in Photo 1. Use pliers to remove any sharp protruding remnants of the can lid (Photo 2). Wash the cans inside and out and dry immediately.
Use needle nose pliers to bend the rim of the taller can into a pouring spout as seen in Photo 3.
Give the solar melting pot and the lid two coats of high-temperature black paint as seen in Photo 4. At this point the metal solar melting pot (Photo 5) is finished.
Step 5: Making the Solar Collector
The solar collector, seen in Photo 1, is simple to make. Start with a large cardboard box that is not too tall. Place a car windshield sunshade on top of the box and push the center of the sunshade into the interior of the box.
Place something inside to create a platform for the metal solar melting pot to sit on. I used a potted plant stand to allow more sunlight to be reflected from the lower parts of the reflective sunshade onto the melting pot. An inverted bucket would also work. I placed a small rack on top of the plant stand to give the solar melting pot a more secure platform to sit on.
Step 6: Adding Wax to the Solar Melting Pot
Use a common vegetable grater to grate candle wax into small pieces as seen in Photo 1. The small pieces of wax will melt easier than large chunks.
Add grated candle wax into the metal solar melting pot (Photo 2). Place the lid on the solar melting pot (Photo 3) and place in a clear plastic bag. Twist the open edges of the plastic bag to close it and place a clothespin over the twisted bag to prevent it from untwisting. Place the solar melting pot in the solar collector as seen in Photo 4.
Leave the setup in place checking every half hour to see if the wax is melted. The length of time the solar melting pot needs to melt the wax depends upon the intensity of the sunlight, ambient temperatures and the amount of wax placed in the solar melting pot. Once you have done this a few times you will know how often you need to check the solar melting pot.
As seen in Photo 5, the white paraffin candle wax melts down completely to what appears to be a clear liquid. The dowel tip is right at the top of the molten wax.
Step 7: How It All Works
The black metal solar melting pot absorbes the sun's rays and heats the metal throughout. After just 10 minutes in the sun, the melting pot is too hot to touch with unprotected hands.
The clear plastic bag acts like a mini-greenhouse heating up and trapping the air inside the bag. This process adds heat to the melting pot.
The reflective car sunshade reflects sunlight onto the solar melting pot so that the sun's rays hit multiple areas of the melting pot including the rear and sides of the melting pot.
This combined approach of harnessing the Sun's free energy is quite effective. The candle wax melts quickly on a hot sunny day.
Step 8: Pouring the Molten Wax
Once the Sun has melted the candle wax, it is time to make the candle.
Molten wax is hot and painful if dropped on the skin. When pouring molten wax, cover exposed skin and wear gloves as the melting pot is quite hot.
Wax can also catch fire if overheated. The solar melting pot never reaches really hot temperatures, but as a safety precaution locate it in a sunny spot free from flammable dried grass and leaves. Frequently check the progress of the metal solar melting pot so that the wax doesn't sit out any longer than necessary.
Place the candle mold inside a large pan before you pour (Photo 1). The pan will contain the molten wax if the mold is accidentally tipped over and spills.
Fill the mold with a small amount of the molten wax and then place the candlewick in the center. As seen in Photo 2, the small amount of molten wax, quickly hardened and secured the candlewick in place.
Pour another layer of molten wax into the mold (Photo 3). Take a short piece of wire and bend it as shown in Photo 4. Place it on the rim of the mold and adjust it so that it supports the wick in the center, ensuring that the wick stays centered while the wax cools and hardens.
I like to pour wax in layers, often adding colored wax to the candle mold.
Set the candle mold aside on a level surface and allow the wax to cool and harden overnight. The cardboard mold acts as an insulator allowing a gradual cooling of the wax which reduces the chance of the wax cracking and splitting.
Step 9: Design Considerations
Colored wax, or even colored crayons can be melted and added in layers to produce colored bands within the candle.
As seen in Photo 2, I added one of my favorite colors to the candle as a layer. Later on, I topped it off with another of my favorite colors (Photo 3) and set it on a level surface to cool and harden overnight.
Candle making is an art. Take frequent notes on what you did or did not do so you can reduce your errors and refine your techniques. Weigh the candles that you like so you will know in advance how much wax you will need to melt for that particular candle. Also note the amount of coloring that you used to achieve the color and saturation that you like.
Step 10: Removing the Candle From the Mold
Once the candle has cooled and hardened it is ready for release (Photo 1).
Remove the plastic lid from the bottom of the mold and roll the cardboard mold between your hands or on a table top. You should hear slight crackling noises as the candle separates itself from the walls of the candle mold.
Take a cloth towel and use it to push the candle out from the top towards the bottom. If the candle only goes so far then resists, roll the mold between your hands again, then push it out further.
Once you get the bottom of the candle out far enough to grab the base, as seen in Photo 2, grab the bottom of the candle and pull with one hand while you twist the cardboard mold with the other hand.
If the candle sticks to the mold, no matter how hard you try to loosen it, you can always cut the cardboard mold to remove the stubborn candle. It is easy to make another cardboard candle mold to replace the cut up candle mold.
Once the candle is free, it will have thin rough edges on the top as seen in Photos 3 & 4. Use the box knife to trim away the rough edges. Use a towel or scrap cloth to rub away any wax film on the outside of the candle (Photo 5).
The bottom of the candle, as seen in Photo 6, is concave because the plastic lid on the bottom of the candle mold was convex on the side in contact with the wax. The concave bottom ensures that the candle sits squarely on a flat surface.
The solar candle is now complete (Photo 7)!
Clean the interior of the cardboard mold with a towel and reuse it for the next candle-making session.
Step 11: Solar Candles
This is a simple and "green" project in that we reuse cardboard and tin cans. Our only energy consumption is that which is freely available from the Sun.
We can even reuse old candle wax by grating it up and throwing it into the solar melting pot.
This simple project would be excellent for school groups or summer camps to share information, in a fun way, on recycling and using renewable energy creatively.
Runner Up in the
Solar Contest 2016