The prospect of spending hours and $ on building a beautiful wood and glass painted wax melter seemed too hard for me. I live in the city, and storage space is a problem. I needed something I could use for other things when not melting wax. Here's my solution:
Get a mid-sized clear plastic storage container with a clear lid. This will be the body of the wax melter itself.
The cappings you want to melt are are put in a paint roller tray. I found a very cheap black plastic one, and cut a one inch square hole in the deepest part. The melted wax all runs down to the bottom and drips through this hole.
To catch the wax, put a large deep tray under the paint tray, but put some fine wire mesh (fly wire type material) over this container. The wax is strained as it drips through the mesh. As well as that, I've found that much of the dark impurities in the wax stays in the bottom of the paint tray and doesn't even make it to the mesh, so the melted wax is quite clean and nice looking.
As I didn't have the right sized wax catching container for the paint tray to sit on, I used two smaller ones, one to catch the honey, and one turned upside down for the paint tray to sit on.
As it's not as efficient as a double glazed insulated solar wax model, I've found that it needs temperatures in the high 20's C (80's F) in order to work. It can melt a lot of wax on a hot day though. I put some newspaper in the bottom of the main body to catch any splashes of honey or wax, so I can still use it for storage when not being used to melt wax. When finished, the paint tray needs to be scraped off and set aside, but the rest can go back into service in the kitchen or garage until you need it to melt some wax.
Let me know if you want some photos.