I found several web sites with information regarding reusing old wax, one of which said you definitely don't put your contaner with wax in it straight onto the heat source. So I needed to find a double saucepan.
Yesterday I went to a car boot sale and right at the beginning I found this tatty old item for 50p which I wouldn't dream of using for food but is fine for melting wax. The wax goes into the top section and water in the bottom pan, whch you then heat. The wax melts without any chance of getting burned by an accidental spill on the heat source. Then I wanted some smallish containers as I didn't know how much wax I would end up with. I found two identical tumblers - quite expensive at £1 for the two - but they'll be reusable in due course.
In the left hand glass is the wax from the remains of a single candle (Spring Bouquet) and the glass on the right has a layer of Creme Brulee at the bottom with Juicy Peach on top of that. Since I found the wax dips around the wick I poured just a little more into the first glass to even up the top - leaving none for the second candle...and couldn't find any part used candles at the car boot I went to today, of course! They'll sit on top of one of my bookcases with a gas lighter so that I can put my hands straight on them when we get another power cut. Now I shall have to scrounge old wax from friends and family!