"Cold Heat" soldering iron; how can it work?

[DizRotus]

You've all seen the ads for the oxymoronically named soldering iron. Has anyone called the 800 number and ordered one? If so, how well does it work?

More important, how can it work? How can 4 AA batteries provide such instantaneous heat?

My guess is that it falls into the same category of that shaker (the motion, not the religion) flashlight that works without batteries; technically feasible, but not practical in application.

I tried one at a Batteries Plus franchise. It works, but you'll go blind from shaking it before it will provide more than mere seconds of light.

[skeptic]

Works pretty well. I've only used it once, so I'm not sure how the batteries will last. It takes a little bit of getting used to, instead of heating up and staying hot like a normal soldering iron, it works like a arc welder (at least thats what it looked like to me). Electrical current is going to each of 2 prongs at the end of the tip. When the solder goes between them it completes the circuit and heats up, basically like you have a short. As soon as you stop, it cools down in seconds. Its worth the 20$ we paid for it, I doubt it would be as useful for a professional who uses it all day, but for a hobbisyt , or someone who does light work its pretty neat.

[Malcolm]

It works OK. Cordless soldering irons have been around for a long time. But the tip technology is new. For my money, I would pay a bit more and get a Wahl Isotip rechargeable soldering iron. Some models only cost twice as much as the Cold Heat unit. The difference in initial price would quickly me made up by the savings in batteries if used frequently, and I don't care if the tip stays hot for a little while longer.

[DizRotus]

That explains it. It's probably worth $20.

Years ago, I used the same principle to cook hot dogs. I attached two forks to zip cord, put a fork in each end of the hot dog and plugged it in. The moisture in the dog completed a circuit and the current cooked the dog; especially interesting with the lights off--but so are many things. It wasn't UL approved; don't try this at home, etc.

Thanks for the testimonial. Your decision to try the "Cold Heat" soldering contradicts your forum ID.

[skeptic]

"Thanks for the testimonial. Your decision to try the "Cold Heat" soldering contradicts your forum ID."

Naaah, as a skeptic I try everything, just to see if it actually works

It didn't hurt that I didn't buy this, a engineer in my company did, and he left it in a shared toolbox for others to try.

[wuzzzer]

.

[lynnm]

The Cold Heat Soldering Iron does work ( I experimented with one a while back that a coworker brought in ). It worked exactly as advertised although one wonders how many connections it can make on a set of 4 AA's before the batteries wear out.I also wonder how well it would handle large joints as one would encounter when working on vintage tube equipment. It certainly handled soldering/desoldering on a printed circuit board without any problem.

My mileage is showing here but when I was a kid I used to buy the old A cells that were about the size of pop cans and had terminals on the top.It was an easy matter to short a piece of 18 guage bell wire across the terminals and watch the copper wire go from copper brown to deep brown to red to orange to yellow and then melt and break the connection.All of this would occur in a second or two.While most batteries have a limited power reserve they can generate an astonishing amount of current flow when shorted.That energy is of course converted directly into heat.

[Malcolm]

A good AA alkaline cell can generate about 2 watts. 2 watts x 4 cells is 8 watts. Cold Heat claims there soldering iron is equivalent to a 25 to 50 watt AC iron. Considering the amount of waste heat radiated into the air in a standard AC iron, and my eperience with the Cold Heat iron and other irons, I would say 25 watts is a fair claim, at least on thin material like PCB traces and small wires, and 50 would be pushing credibility.

[DizRotus]

The arc explains how the solder is melted, but it doesn't seem like it would do a good job of heating the surrounding joint to allow the solder to flow into the joint. Notwithstanding that intuitive reservation, I defer to the comments of those here who have actually used the things.

[Dave_H]

I bought one at Radio Shack and wound up returning it so I would have to give it a thumbs down. When I tried to tin a wire it acted just like the strand across the battery in Lynnm's post. Cherry red. The tip is made up of two conductive ceramic? elements separated by a thin insulator. As noted before you basically short out the tip and generate heat in the component being soldered. I tried it on a ring terminal also and the heat buildup was too gradual - the insulation on the wire began to melt. With a conventional iron you are transferring heat to the joint and have better control of it. I suppose I could have played with it more and maybe got better results but it did not look very promising. Be aware that I have been soldering electronic gear for 40+ years so it could be an old dog/new tricks issue.

Dave H

[Malcolm]

I don't think its your technique. Being equivalent to a 25 W soldering iron, it is likely to melt insulation or lift traces before heating the metal hot enough to melt the solder if you are not careful. I have seen more boards ruined by using too small an iron that too large. I typically use a 40 W iron. It brings the metal up to a temperature high enough to melt the solder before enough heat to cause problems has dissipated into the work.

[IndyKlipschFan]

I bought mine at CVS pharmacy.. for those few times I have needed it it works fine.

19.99 quite the deal IMO. (Includes solder too)

[D-Rex]

My dad has a liquid gass powered soldering iron. About the size of a mid sized screw driver, you light the gas in a little chamber on the iron and away you go. It was handy but my soldering skills lack much to be desired!