I wired a triac inline with my cheap soldering iron. I turn it down a bit to save the tip during regular operation (it gets too hot at full mains voltage), and

I wired a triac inline with my cheap soldering iron. I turn it down a bit to save the tip during regular operation (it gets too hot at full mains voltage), and I turn it way down if I'm doing something else for a minute so it stays warm. The triac mangles the sine wave, but this resistive heater doesn't mind. I did this on a whim but it ended up meeting my needs quite well.