When it comes to rendering beeswax, nothing works as well as a solar wax melter.
Solar melters are commercially available and there are numerous plans around form which you can make your own. However, there is no need for an amateur beekeeper with a few hives to spend more than a couple of dollars on making an effective solar wax melter. Such a melter can be used to melt down and recover the wax in cappings, burr comb and comb scrapings or pieces.
The basic elements of this small solar wax melter are a polystyrene box and a pane of glass. Second hand polystyrene boxes are freely available (if you haven’t already got one in your shed) from many shops, as they are commonly used for bulk packaging. A suitable pane of glass is normally available from recyclers (e.g. Revolve at Mugga Lane or Belconnen waste disposal centres) for $1 to $5.
Place the glass on top of the box!
Further development is limited only by your imagination. The melter photographed above has been tilted towards the sun with a house brick. Inside it has a $3 chip frying basket hooked over a 5 litre icecream bucket ($0). The basket is lined with a Chux Superwipe as a filter paper and is filled with the cappings (compressed by hand) from about 12 extracted frames. This setup has produced some lovely clean wax blocks.
The next improvement to this melter will be an internal lining of aluminium sheet ($1 from Revolve) painted black. This will further increase heat absorption and melter effectiveness.
Hint: Rinse honey from the cappings and comb with water before melting. Put a little clean water in the bottom of the wax collector (icecream bucket). This water will dissolve / retain and remaining honey or other contaminants. Once the cappings are melted and the wax solidifies, remove the water from the collector, rinse the bottom of the wax block and re-melt the clean wax in a suitable mould (a 2 litre icecream container?) or pouring jug.