Built a solar wax melter from an old window — design notes and actual temperatures

Finally built the solar melter I've been talking about for two years, and Alentejo sun turns out to be extremely good at this job. Build: plywood box painted matte black inside, an old double-glazed window as the lid, sealed with weatherstrip. Inside, a slanted metal tray (old baking sheet) holding the comb, draining through a strip of paper towel as a filter into a bread tin with a little water in the bottom. The whole box is tilted about 30 degrees to face the midday sun. Numbers, since I know people will ask: cheap oven thermometer inside read 85-95C on a clear 33C afternoon. Wax melts around 63-64C so there's plenty of margin — it processes a tray of cappings in a couple of hours. The slumgum stays behind on the towel and the wax comes out shockingly clean and bright yellow. Total cost: zero euros, everything scavenged. Should've built it years ago.