Okay, I feel like a sucker, but I just saw this infomercial-style 30-second commercial for a product called Cold Heat. It's a cordless soldering iron that instantaneously turns hot and then cold again. Sounds like science fiction, especially since they're selling the thing for $20, but unless they used gallium-based fake solder for the demonstration, I'm kinda convinced.

Anyone else heard of it? I'm almost inclined to throw away $20 just to see one.

Actually, it looks like they sell 'em over at ThinkGeek.

Please do (kindly throw away $20) and give us your unbiased review

I haven't used one, but here's my take on it.

Crap.

Seriously - they show an image of someone reworking what looks like a graphics card with it. That's a quick way to kill it IMO.

Their selling point is the speed at which it heats up and cools down. That tells me that the tip has a very low heat capacity. They also tout the 800 degree temperature, and in the FAQ go on to say

Quote:
5. How hot does the material get?
Cold Heat tools may achieve temperature levels well over 1,000F, but the exact temperature can be controlled through proprietary means.

This tells me that the temperature is not user-adjustable. The 'proprietary means' are likely to be a preset PWM power scheme in conjunction with the surface area of the tip (which affects cooling rate), ie, this iron is constant power, and the temperature depends on that power and the thermal loading of the work.

What does all that mean?

It is very hard to judge exactly what temperature you are soldering at. If you hold the bit on a small part for a few seconds then you could end up heating the part to 800 or 1000 degrees Fahrenheit. And with the low thermal capacity of the bit, the iron might not be capable of putting enough heat into a large component to be able to form a good joint quickly.

Both of these situations are undesirable. The former is likely to exceed maximum temperature ratings and lead to dead components and lifted PCB tracks (too much heat kills the bonding between the copper and the substrate). The latter is likely to cause poor solder joints, and can cause other bad effects in some components (eg NiCd or NiMh cells, capacitors) when it takes so long to heat the lead of the component up to solder temperature that the rest of the component gets that hot too.

Add to that the fact that the iron is not static safe either, and you can see why it wouldn't be let near my empeg,

If you really want a handheld portable soldering iron, then I'd recommend a butane powered one such as Portasol. They too are constant power (as opposed to constant temperature), but at least that power is easily adjustable so that it can be tailored towards different thermal loadings. With practice it is possible to do quite fine work with it, although you still have to worry about static issues.

But a real temperature controlled iron easily beats that too.

a few years ago I had a unit that was (sorta) like that cold heat thing. in short, it sucked. they should have just called it 'cold luke warm'
I'm a big fan of the butane type, the one I've had for 10 years is a 'pyro-pen' came with a few very nice tips including a heat-shrink attachment. the only real drawback is that it's noisy, but at least I'm less likely to leave it on.
it's small, light, easy to hold, has a great cap you can pop on even when it's still hot.
best thing is that it'll handle small and large jobs, heats up very quick, and for ten years has been without problems with medium to heavy use.
you will need to keep a can of butane gas around.

hth.

They showed that on techtv and said it doesn't get hot enough to do much with.

From the web site:

Quote:
The spark (arc) is caused electrical current passes from one half of the tip to the other. Although the tool's spark should not damage any electrical or electronic components, we recommend caution when soldering sensitive components. Also, ensure that the tool is not used in flammable or explosive environments, such such as near gas or gasoline fumes.

Um, it's a tiny arc welder. This would be like using a tig welder to work on static sensitive machines. I can't imagine even the most robust of chips surviving a close encounter with this thing...

It's taser capabilities might be worth exploring.

Specifically, I'm next to positive it's an ATI graphics card. I just don't understand why they're about to solder the top of the heat sink. Likely they don't want to get close to any components.

I see this thing being useful for soldering lamp cord or doorbell wire - like in their animations. Or jewelry items and other craft-type hobbies. They don't show any animations of someone working on SMT parts or anything like that.

Bruno

Well, honestly, I wasn't really considering it for doing precision electronics work. (I'm not considering using me for precision electronics work.) I just thought it looked neat and good for coarse soldering and the idea that it cooled down immediately was neat.