How cold heat™ works
Posted by Matthew
Everyone has seen the infomercials for cold heat™ soldering irons. They seem to answer all the easy questions. How much does it cost? Can anybody use it? Can it replace my old worn out iron? However they leave out the most complicated question. How does cold heat™ work?
This circuit remains broken until you put something conductive, like solder, in contact with both halves of the tip. The solder completes the circuit… Resistance in both the solder and the tip produce heat, and the solder melts.
Personally, I have never used a cold heat iron. Everyone who has either love them or hates them. How Stuff Works was more comprehensive than your friendly infomercial and mentioned a few downfalls they came across.
We suspect that they have the knack for using just the right amount of pressure at just the right angle, completing a circuit without shorting out any electrical components being soldered or breaking the tip.
I was always taught that the #1 rule of soldering was that you heat your work (the part to be soldered) with the soldering iron and then apply the solder to the work directly. You only put a small amount of solder on your iron to act as a heat bridge. You do NOT transfer solder from the the iron to the work unless you’re working on a very small joint, such as you might find on a tiny circuit board.
If the Cold Heat only heats the solder, then it’s fairly close to useless for a large number of tasks because you’ll end up with a crappy cold joint of dubious reliability.