Deception In Soldering Iron Ratings

[spec]

I use a 1950s traditional soldering iron with a huge square copper bit for doing heavy soldering- it works a treat. It has no electrical heating element; you heat it up in a gas torch. It's not too good for surface-mount work though.

spec

 

[MrAl]

Hi,

Very interesting tool. They probably used that on lead piping
Also looks like a medieval torture device

 

[spec]

Hi,

Very interesting tool. They probably used that on lead piping
Also looks like a medieval torture device

Yes, its not intended for electrical work, but mainly for tin bashing, and the like.

I use it for copper bus bars, about 7mm in diameter, in audio amps, power supplies, etc.

It feels like a medieval torture device if you grab the wrong end.

spec

 

[throbscottle]

I once used an iron similar to that (smaller, the end was about 1/2" to a side) to do something involving soldering pins of the 40 pin dip inside the multimeter I used to have, because my Antex had died
I think the meter must have had a dry joint somewhere - can't remember now. It was awkward, but do-able.

 

[spec]

The blacksmiths iron is also handy when you need to use high melting point solder.

Or if you have a ranch and want to mark your cattle with the 'Lazy Iron' brand.

spec

 

[MrAl]

Hi,

Oh, those poor cows, ouch
But then they go right back to eating grass as if nothing had happened.
I think it may have been on "American Dad" or "Family Guy" where they were branding a cow and it was going, "Oh yeah, yeah, yeah", as if it liked the pain from the branding iron. That was funny

But hey you reminded me of my mini torch/soldering iron. The one i got was from Dremel. It's a mini torch that runs on butane and has a soldering iron tip attachment. Turning the torch on low the tip gets pretty hot pretty fast. Solders nicely i'd say small to medium size electrical soldering jobs. Might not do #6 wire but it should do #10 wire for example. Nice little invention. There are other brands too.

On the other hand, my "Cold Heat" soldering iron should be called "Cold Crap" as it is very hard to use and makes crappy joints when it does work, and the tip breaks easy.

 

[spec]

Of course, real men use silver soldering and macho men use brazing, both very useful techniques.

I have used silver soldering for repairing hand lamps and staplers, for example- works a treat and doesn't distort the base material too much. I also made a muffler, that was no longer available, for an old motorbike, using silver soldering.

And made a complete exhaust system for my third automobile (Vauxhall Victor FE) by brazing gas pipe- it weighed a ton and sounded very odd, like a sumo wrestler far**ng down a err... gas pipe. When I took the Victor to a garage for an MOT (UK mandatory yearly road test), the mancanics laughed their sides out. As time went on the Victor rusted away , in spite of all my MIG welding, and all that was left in the end was my gas pipe exhaust.

spec

 

[MrAl]

Hello again,

Well i have to commend you on doing that rework mod on the exhaust system as i would have liked to do that on my old Hyundai. In the 20 years i had that car i went through 5 exhaust systems! Yes, front to back, entire systems, five times, because the pipes one of the Meineke shops used were too cheaply made. The last system i went to another shop and got better pipes even though they were a smaller diameter than the car had originally.
I would have liked to install a custom set of pipes on that thing that were made of thicker metal, but it would have been very hard to do on that car so i had to keep buying systems. One time i got away with a single pipe purchased from an auto parts store for a good price, but then they stopped making those pipes so they had to be made custom from a shop like Meineke. That's one good thing about them, they make custom pipes to fit any car.

 

[Sinedup]

PMPO rating is another one that fools many potentials customers into believing their 'boombox', car sound system, etc actually produces that level of output.
Years back, an active crossover for a car (12 V DC) had what appeared to be 150 W POWER!! on the packaging.
Opening the box lid, the X-over was screen-printed 15 Watts.
Upon closer inspection, the Samurai background graphic on box packaging had a small period, camouflaged as part of the sword handle.
No extra spacing 'tween 5 and 0.
Crafty..

 

[Tony Stewart]

At my 1st job in aerospace NASA soldering bible ( about 3" thick) was taught to all techs using 30W 1/16th tip with triac dimmer for temp control.
During early 90's some used 550'F controlled tips that self regulated others 600'F for bulk parts. I use a 75W with a dimmer.

 

[MrAl]

Hi,

75 watts is pretty good, if it really is 75 watts.
Many of the irons/stations i have seen for sale tout "60 watts" but really they are much closer to half that. That's what prompted me to start this thread.

On a related issue, i got a soldering GUN from Harbor Freight and the tip burnt out after a few uses. A friend bought one too, same issue. I replaced my tip with a regular copper time but the gun body overheats quickly, so i have to use it quickly or use a variac with it to lower the input power.
So my recommendation there would be not to buy that particular soldering gun. It's the only one they sell right now and is bright orange in color.

 

[picbits]

On a related issue, i got a soldering GUN from Harbor Freight and the tip burnt out after a few uses. A friend bought one too, same issue. I replaced my tip with a regular copper time but the gun body overheats quickly, so i have to use it quickly or use a variac with it to lower the input power.
So my recommendation there would be not to buy that particular soldering gun. It's the only one they sell right now and is bright orange in color.

Sounds like the old soldering gun I used to have from Tandy (Radioshack) - it had written on the side to only use for a certain duty cycle - I think you could only manage around 30 seconds or so at a time.

 

[Tony Stewart]

the biggest problem with soldering irons is careful maintenance each use and getting the heat to the tip from thermal resistance in the screws, barrel or plating. My old friend who did stained glass lead soldering for over 40 Years was surprised when I told him about Nasa’s solder training handbook in the 70’s that was as thick as a few bibles. My tech’s least favourite job was rewiring a few centre wires on a 50 pin miniature cylindrical Canon connector.

 

[picbits]

the biggest problem with soldering irons is careful maintenance each use and getting the heat to the tip from thermal resistance in the screws, barrel or plating. My old friend who did stained glass lead soldering for over 40 Years was surprised when I told him about Nasa’s solder training handbook in the 70’s that was as thick as a few bibles. My tech’s least favourite job was rewiring a few centre wires on a 50 pin miniature cylindrical Canon connector.

Have you ever used the Oki / Metcal irons ? I've never found anything that can compete with them for being able to get heat into a joint in a hurry but also precise enough for precision soldering.

When I teach new interns how to solder, I demonstrate how you can solder together a couple of BNC plugs or 9 Pin D sockets in seconds - using a conventional iron, they suck the heat out almost instantly but with the Metcal you get an amazing amount of localised heat before the rest of the item you're soldering heats up too much.

 

[Tony Stewart]

I recall entering a METCAL contest at some epic Vegas PCB trade show when they used to fill huge halls with pick N place machines . How many SMT memory chips can you remove in 10 seconds?

I think I did around 12 chips but far from the winner. RF surface heat can’t be beat.

 

[KeepItSimpleStupid]

When I teach new interns how to solder, I demonstrate how you can solder together a couple of BNC plugs or 9 Pin D sockets in seconds - using a conventional iron, they suck the heat out almost instantly but with the Metcal you get an amazing amount of localised heat before the rest of the item you're soldering heats up too much.

Resistance soldering (American Beauty) works nice for pins too. Basicaly tweezers with (Stainless steel pins). At least, that's what I used.

It might even be superior to the RF because you can't accidently get solder on the pins. RF with a non-tinned tip might work as well.

 

[Tony Stewart]

It’s user skill that degrades tool performance.

Metcal transfer speed of heat velocity to the surface is in milliseconds. Then down to the unwanted area it slows down due to incremental heat mass. For example on 5mm LEDs the wire pin keep out zone for solder is typ 5mm below the epoxy base because the heat velocity I measured at 1mm/s so the spec of 5s max for hand solder will not reach full temp to the gold wire bond creating shear stress. This is why I told my client they must learn to solder these in <=3 sec for reliability margin. The epoxy also gets soft (glass transition temp is lower for clear epoxy) around the wire leads and moisture ingress risk is accelerated rapidly leading to outdoor field defects.

The same would be true for Dsub plastic transition temp. and warping pin alignment. So the heat transfer time to soft plastics must be much greater than max solder dwell time. Or learn to solder a wire by pretinning both ends and bonding a small wire in <3s is a target time. Or <0.5s if you are good.with a METCAL.

 

[JimB]

At the other end of the soldering iron range, I came across these no nonsense items in a museum in Germany earlier this year.

Big and chunky for a variety of applications.

Here is something different, petrol powered soldering irons, they have a built-in blowlamp...

... as illustrated in this poster.

JimB

 

[MrAl]

Hi,

Wow, what a selection
I had an old one that was very big but it was electric too. Maybe 300 watts, cant remember now.
I considered getting a big soldering gun but did not get it yet. I think it is around 400 watts.
I have used the big copper soldering tip on a big propane torch too, but dont have it anymore.

 

[Metor]

Hello there,


QUESTION #1:
You are shown two temperature controlled soldering irons, one is 60 watt and one is 40 watt. The 60 watt iron is slightly more expensive than the 40 watt iron, but not much more. Which one do you purchase?

QUESTION #2:
You are shown two temperature controlled soldering irons, one is 60 watt and one is 50 watt. The 60 watt iron is slightly more expensive than the 50 watt iron, but not much more. Which one do you purchase?

QUESTION #3:
You are shown two temperature controlled soldering irons, one is 60 watt and the other one is either 40 or 50 watt. The 60 watt looks a little cheaper in quality but not too much cheaper. Which one do you purchase?


If you answered "The 60 watt iron" to either question above, you probably paid too much for that iron because guess what, they are all about 40 watts !!

In various ad's on the web we see 60 watt irons that are the exact same model as the 50 watt irons, yet they are both really only 40 watts. This means they cant solder as well as a real 60 watt iron for somewhat larger metal joints.

First we see the 60 watt rating, which appears in ads for companies that dont seem to care about what they say about their product as long as it sounds good. Then we see the 50 watt rating, where the company is a little more responsible about their rating because they take their rating directly from the heating element which is stamped "50 watts, 24 volts". So we cant blame the companies that advertise 50 watts.

Measuring the DC resistance, we see that the "50 watt 24 volt" element resistance really measures 16 ohms. The power delivered to a 16 ohm resistance with 24 volts DC is:
P=24^2/16=36 watts.

So the elements are not even up to 40 watts yet !

The way it looks is every time the product changes hands the receiver tacks on another 10 watts, so that by the time the ad gets posted it's up to 60 watts in some cases.

That's quite deceptive because we purchase items based on what we need, and sometimes we need the higher power iron but we dont get that, when if we knew the actual rating we would get one that really fit the job.

You'll note that many soldering stations use AC not DC, but that only makes matters worse if there is any inductance because that can only lower the wattage not increase it.

One manufacturer that was contacted actually said that the "60 watts" came form the "input power to the station". But that's not accurate either because the input power with only the iron running is not anywhere near 60 watts. It's also very unlikely that a small control board and transformer would consume 20 watts of power when powering a 60 watt device on full power.
When informed about this, they simply state that you can return the entire station for a refund.

Please note that this doesnt mean that the irons dont work at all, they do, but they wont be as high powered as expected. For example, i had no trouble soldering a #24 gauge (AWG) copper wire end to a 10 turn Bourns potentiometer terminal, which is about 1/8 inch wide and about 1/8 inch long and thin metal. Didnt try #12 AWG wire yet though.

If you have any comments that would be nice to hear, or if you have any experience with these irons. The elements themselves are often advertised as "50 watts 24 volts DC".