These projects may cause cancer in California.
This soldering iron lives in my backpack, always ready for emergencies. It shares the power supply with my thinkpad so I don't have to carry another brick. It uses a Hakko T12 tip and drives it with an op-amp based controller, which heats up to working temperature under 10 seconds. It was a late night hack to find a use for a T12 soldering tip with faulty connection. It have been one of the most frequently used tool in my backpack. I have thought about machining a nice aluminum handle for it, but I decided to keep it sketchy because I enjoy seeing people's reaction.