Hi Anthony
I use iron wire for the wrap then completely cover with ordinary household soap, well rubbed in. I heat the mass slowly in a Bunsen burner flame or gas ring depending on the size. This ensures more even heating. Depending on the tap material the tap can be quenched in new engine oil, or water. Oil is less severe than water. After hardening if the tap is high carbon steel it will need polishing and then tempering to light straw colour. This is best achieved using a small steel lid filled with fine sand, to evenly heat the tap, and carefully heated from beneath until reaching the required colour, then quenched. If you are not experienced in this technique, try it on a similar size nail, as the timing can be tricky.
Good Luck David