I have a hot tub, and I burn a lot of candles and incense for mood lighting. I buy them cheap at Goodwill and The Salvation Army, so they are always different sizes and shapes and colors. They burn down but there are always leftover scraps, and over the years they have collected. And what does a Geek do with scraps? They MAKE STUFF!!!

Step 1: Accidental Candlemaking

I put candles I purchase in my gazebo where the hot tub is located. Living in Las Vegas, the Vegas sun can get pretty fierce and I discovered that the extreme heat fused several candles, bending them in interesting shapes. The idea of Solar Candle making was born.

Step 2: Building and Melting

I purchased a tall flower vase at Marshall's. It has thick glass which I figured can withstand the heat of the candle, and I started throwing assorted shaped and colored pieces of old candles into the glass vase.

The only real care I took was that I made sure there were no leftover wicks.

I let the glass sit out in the sun and over time all the wax melted and started merging with the other colors giving a great effect. Some parts melted into looking like something floating.

I have included two photos of the sun doing its work.

In future iterations I may add a layer of color at a time to give a strata effect, I also may try swirling the hot wax with a large wood stirrer and a drill.

Step 3: Chopping, Grating, Slicing, Shaving

Using a piece of wood, I shave away at a block of white wax that's been sun warmed, and am making a layer of wavy white shavings. You can also use a cheese grater to get a nice fine amount of wax that will melt faster, and also can be used for multiple purposes.
Use a larger piece of wood to tamp down the wax as it cools to get rid of any air bubbles, and give you a finished look.

Step 4: Finishing the Projects

After the candle is at a level and pattern you like, it's time to embed a tall thin candle (I'm calling a wick candle). With the wax still hot, just push the tall wick candle into the hot wax. Freezing the candle will make it even firmer.
If you are having trouble putting the wick candle in, you can also drill a hole using a wingbit / hole bore.

But you gotta be careful not to drill into the glass bottom.

This is not a few hour project; it will take days or weeks till the wax is uniformly melted, and, depending on intricacy of it, can be meticulous work.

If you don't live in Las Vegas, use a large lobster pot and boiling water. Be warned people: you are dealing with a large glass vase filled with very hot wax, and you can harm yourself, burn yourself or end up a display at Madame Tussauds.