Cold Heat Soldering Iron ?

[Megamox]

Anyone used one of these "Cold" heat soldering irons, Saw one on TV looked nice, was hand held, claiming the same sort of ability as normal irons. Interested in any opinions before investing RRP £19.99.

Megamox

 

[Nigel Goodwin]

Anyone used one of these "Cold" heat soldering irons, Saw one on TV looked nice, was hand held, claiming the same sort of ability as normal irons. Interested in any opinions before investing RRP £19.99.

There was a thread about these a while ago, general opinion is that they are a useless toy!.

They certainly wouldn't be any good for electronics and for building things.

 

[monkeytree]

i remeber commenting on these (if i remeber i got banned of for saying (this is in words so dont ban me) that they seem to be starstarstarstar) please dont ban me nigler,please

 

[jrz126]

I think they are a waste, although if I was in the middle of a field or something and I needed to solder something, thats where I can see it coming in handy. For typical soldering work though, not very practical.

 

[Roboticinfo]

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I have one and it works well, if I go to a robot show and I need to make a quick soldering job I would use that, but not for sensitive stuff because it could fry a circuit depending on what you like to do.

In my opinion it is good for soldering small thing's like relays, switches, Sockets and elec.

If it was a scale from one to ten I would give it a 6.5

 

[mahinda jayasinghe]

Could any one tell me how it works. or on what basic principle.

Thanks

 

[Roboticinfo]

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It is a cordless soldering pencil and basicly it only melts solder so if you touch with your hands when it is on it will not burn you but when you touch solder it heats up to 800f and cools back down in 1 to 2 seconds and you can touch it.

It runs on double as and the replacement soldering tips are $10.00 USA

 

[zevon8]

It is what is known as "resistance" soldering. There are two electrodes at the tip, with a voltage applied to them. When you touch both of them to a conductive material, a current will pass through what is basically a short circuit, and the material rapidly heats up. The tip only gets hot by picking up the heat from the material that heated, the tip itself having little mass, cools quickly.

Resistance soldering has been used for decades in industry, it has its place, but for general electronics use I don't find it a very usefull method.

If I really need cordless soldering, I would either get a rechargeable iron, or a butane powered one. The nice thing about the butane powered ones is that they have many tips available, and can also be used as a source of hot air for heat-shrink, reflowing solder, even SMT work.

 

[pike]

It's really quite useless in this field, only a load bearing joint of say steel would benefit from this kind of welding. ( so the steel doesn't become distempered)

Useless toy really, as said before.

 

[mstechca]

heh

didnt someone have in their signature something like "never stir cold coffee with a hot soldering iron"?
lol

 

[samcheetah]

yeah i think its tansis :lol:

 

[Eclipsed]

I have one, I think it is pretty useless.You can only solder very small joints, and you definately can't touch the tip right after soldering(tried it, ouch).Another downside, the tip is rather large

 

[Roboticinfo]

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I would agree with you there but I didn't have that problem if you wait for 4 seconds.

 

[Eclipsed]

It wasn't too smart of me, I was just mimicking the TV commercial though.

 

[Roboticinfo]

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LOL

:lol:

 

[Nigel Goodwin]

Don't they work by passing current through the solder, causing it to melt?.

Not a 'cold' process at all, just that you are supplying electrical energy instead of heat energy - rather like a spot welder.

From a soldering point of view it means you can't get a decent joint! - good soldering requires heating the JOINT, then applying solder to the JOINT - you don't heat the solder directly.

 

[eblc1388]

Don't they work by passing current through the solder, causing it to melt?.

EXTREMELY unlikely. :lol:

I tried passing 50A to a solder joint for 10 seconds and it just slightly warm to the touch.

Unless the "thing" puts out 500A then that's another matter.

 

[Nigel Goodwin]

Don't they work by passing current through the solder, causing it to melt?.

EXTREMELY unlikely. :lol:

I tried passing 50A to a solder joint for 10 seconds and it just slightly warm to the touch.

Unless the "thing" puts out 500A then that's another matter.

Trying putting a piece of solder across a car battery! - you will soon see that it gets more than 'slightly warm' :lol:

In fact, putting a piece of solder across a reasonably sized charged capacitor vapourises the solder! - you wouldn't need anywhere near 50 amps to melt it - I can only presume your measuring was in error? (do you have a meter that will even measure 50 amps?).

 

[eblc1388]

Trying putting a piece of solder across a car battery! - you will soon see that it gets more than 'slightly warm' :lol:

Is the current anywhere near 50A by putting a direct short across the 12V car battery? Or it is much higher?

In fact, putting a piece of solder across a reasonably sized charged capacitor vapourises the solder! - you wouldn't need anywhere near 50 amps to melt it

This time I agree with you because you are referring to a solder wire instead of the solder joint. The test is easy to do. Just pass 50A to a solder joint(I did my experiment on a solder joint on a PCB) and see if it melts.

But you have to take my word for it if you do not have a 50A power supply.

Using the capacitor as an example is a bad idea simply because even a 100uF charged capcitor, when shorted, would produce current in excess of 100A. In case of suitable sized capacitor, it can be much higher.

I can only presume your measuring was in error? (do you have a meter that will even measure 50 amps?).

50A is a small current to me. I worked on a DC rectifier that gives out 40KA and I do not have a meter that measure 50 amps.

But I do have a shunt that measure 400A and I hope that's good for the purpose.

 

[eblc1388]

I did a seach for more information about the soldering iron on the net and Nigel and others are right. My apology to them.

The soldering iron does rely on passing current through external contact to generate the heat required.

I think my 50A test is inconclusive and failed because:

1. the wire I use to pass the 50A current is too thick so it carries part(i.e. most) of the heat away.
2. the gap between the wire contacts are too wide, on either side of the joint
3. the PCB underneath conducts away the heat

Even so, why a device with only 4 alkaline batteries can melt solder is hard to understand. I did used a similar device in work but that works on Ni-Cd batteries instead.