Crappy soldering irons

[Stonent]

I don't solder enough yet to have the need for a station, so I use a butane soldering torch for the occasional fix-up.  The other day I thought I was out of butane and needed to fix a lamp cord so I dug out my old Weller 40w iron I've had for 20 years but haven't used in forever.

I let it heat for 30 minutes and then tried another 30 to get the wires joined.  The solder kept beading up on the wire.

I finally gave up and turned out I did have more butane. I had it all done in less than 2 minutes with the butane torch.

So the question is, why do these plug in irons even exist if they don't seem to work ever? (And I was using standard 60/40 solder as well)

[andtfoot]

I'm pretty sure 20 years of corrosion would have the same effect on any soldering iron.

I use a plug in soldering iron all the time and it works for me. 

[AG6QR]

How thick was the wire?  It takes a lot more heat to warm up heavy gauge wire than to heat small leads on electronic components.  The heavy wire conducts heat away from the soldering site. 

However, I'm not sure I understand what happened to cause the solder to bead up.  The normal technique is to heat up the wire with the iron, and put the solder on the side of the wire opposite the iron, so that the solder only melts after the wire is hot enough to melt it.  If you use this technique, the solder won't bead up, unless maybe the wire is really really dirty and corroded, needing lots of flux.  What happens instead is that the solder won't melt if you don't have enough heat to warm the wire sufficiently.

Lots of corrosion on the tip would also reduces the ability of the tip to conduct heat to the soldered metal.  If the tip was stored well-tinned, it may be ok, but if not, that could be the problem.  Is the tip nice and shiny now?  Does the tip wet with solder well?

I've used cheap small irons for small electronic components.  They don't work nearly as well as a proper temperature controlled iron, but they will solder small things well.

[Stonent]

It was whatever gauge a stranded lamp cord would be. Basically the copper wire was sucking so much heat (by my estimate) that the iron just couldn't handle it. But you are right, the iron was a bit dirty but I didn't think it would matter much from heating the copper wire from the back.

[G7PSK]

What I call an old fashioned soldering iron work very well, unless you have lots of dirt and corrosion on the tip or between the tip and element, what they don't like is to be left on unattended for long periods as they have no thermal control other than heat being removed by conduction so the tip will burn/corrode rapidly if on and not used within a few minuets.

[Zero999]

Yes it sounds like corrosion. The cable on a desk lamp will typically be 0.75mm² maximum, so a gas iron should be able to handle that with no problem.

The cheapest iron I've used was a 12W 12V iron I bought from a discount store and ran off a halogen lighting transformer and even it could've done this.

[azi]

Sorry, but in my opinion, you are using a crap tool.

I got a butane soldering iron once out of curiosity, and my conclusion is that the only thing it was good for is if you need to do an emergency repair and you don't have electricity.

I still don't have a full soldering station because they are expensive and take up a lot of space.

The usual advice I've read from experienced "pros" is that "you NEED a temperature-controlled soldering iron and stop wasting your time with cheap junk!" I used to read that all the time when I was getting started. I found it annoying and I kept resisting upgrading because of the reasons just mentioned. I was using cheap tools from Radio Shack and similar, thinking they were ok for what I was doing.

And as all those people said, I was just plain wrong. The difference is this: with a cheap iron, maybe you can make the connections, but it's difficult at best to do it right.

With any decent temperature-controlled iron, soldering is easy and you can make beautiful and technically-correct solder connections quickly. It makes soldering into a pleasure. I used to think I had tools that were ok, but I was just bad at soldering. Once I got a good-quality iron, everything changed.

I said I still don't have a full soldering station, so here is how I got a really good soldering iron for a more affordable price: The Weller WP25 is a simpler product that is just a good-quality plug-in soldering iron that is temperature controlled. The difference is that it has only one temperature, unlike soldering stations that allow you to set the temperature. It is only $38.50 at Mouser. I suggest you try that.

[Maximus64]

Need a better soldering iron. I recommended Weller Brand soldering station.

[drake]

A pretty smart guy once told me "the tools make the trade" and to be honest having the  right tool, in this case a decent soldering iron, turns soldering into cakewalk. The reason radio shack sells cheap irons is because they are mostly dealing with newbies that are just starting out and don't want to budget big dollars in an auto temp controlled station just to make an led blink, which is fine to get started with. But they tip on you iron is probably worn out too, making matters worse.

[Fsck]

A pretty smart guy once told me "the tools make the trade" and to be honest having the  right tool, in this case a decent soldering iron, turns soldering into cakewalk. The reason radio shack sells cheap irons is because they are mostly dealing with newbies that are just starting out and don't want to budget big dollars in an auto temp controlled station just to make an led blink, which is fine to get started with. But they tip on you iron is probably worn out too, making matters worse.

ditto: going from radioshack -> Hakko 936 -> Metcal STSS, every jump was pretty amazing in terms of how much better it made the experience. the 936 made soldering easyish, but the metcal really makes it pleasant.
even a hakko 936 clone will probably make your life way easier for a minor investment.

[IanB]

So the question is, why do these plug in irons even exist if they don't seem to work ever? (And I was using standard 60/40 solder as well)

But they do work.

Questions:

Did your Weller iron reach a temperature where it readily melted solder on the tip?

Did the solder wet and flow over the tip of the iron so it was nice and shiny, or did it ball up on the iron when you applied it?

Did you use a little solder on the iron tip to help transfer heat from the iron to the wire?

Did you use extra flux on the wire to help the solder flow and make the join?

[simpson]

You just need a quality iron (properly tinned) such as a temp controlled type from Weller, Hakko, etc.

[deth502]

i dont have a temp controlled station either.

i have a 25w weller, a 40w weller, and one of those hand held gun type/trigger ones.

i can concur that the 25w weller has much difficulty with larger ac sized wires (16+ ga, your lamp cord was likely a 14 ga) the 40w works great for doing these all day long. the gun type iron heats up quick and is great for doing 1 or 2 large joints like this.

also, a little extra flux works wonders sometimes as well.

eta, just re-read the op and saw you did have the 40w and not the 25w. so, yeah, either needed flux or that iron's broken.

[Robertmaks]

There might be a problem with the coil inside or a loose connection. I had a soldering iron that did the same thing so I measured the current draw and when I moved the wire I lost connection and when I moved it back it regained connection, so there was a problem with the cord. It was also a old soldering iron from my basement from about 25 years ago, but in mint condition. Just buy a new one, and they heat up in 5 minutes and get one that is adjustable, for about $10.

[Greyersting]

There are 2 reasons I can think of for why the crappy ones exist.
1. People don't know enough about it to know they are crappy
2. Someone needs a quick iron for a quick job

Currently I am at reason #1.

[Sar]

I'd been using basic corded irons forever and had the usual experience. I had probably $150 worth of soldering irons sitting around at one points. Small ones for fine work, big ones for heavy stuff and a bunch in between grounded/ungrounded, etc. 

When I did my first contract surface mount project I knew I needed something better to make life easier so I ordered one of those basic temp controlled irons from SF with the fine point and flat blade tips. HUGE difference and, as far as soldering, it works pretty close to the bigger solder/desolder station I use at the office and has replaced all those wall plug soldering irons of various quality that junk up my workshop.  It warms up in about 30 seconds too! I think a 'good' wall plug soldering iron is $15-$20 and the SF one was $35 or $40 or something along those lines. Do the math and stop your suffering

[deth502]

I'd been using basic corded irons forever and had the usual experience. I had probably $150 worth of soldering irons sitting around at one points. Small ones for fine work, big ones for heavy stuff and a bunch in between grounded/ungrounded, etc. 

When I did my first contract surface mount project I knew I needed something better to make life easier so I ordered one of those basic temp controlled irons from SF with the fine point and flat blade tips. HUGE difference and, as far as soldering, it works pretty close to the bigger solder/desolder station I use at the office and has replaced all those wall plug soldering irons of various quality that junk up my workshop.  It warms up in about 30 seconds too! I think a 'good' wall plug soldering iron is $15-$20 and the SF one was $35 or $40 or something along those lines. Do the math and stop your suffering

sf?

[Gert Kotze]

I agree with Sar I have also tried using the cheap irons that are not temp controlled and suffered a lot unlit I bought myself a fairly decent solder station from weller and now soldering have become a joy.

[Jibby]

Low cost and siplicity.

[ciccio]

There are 2 reasons I can think of for why the crappy ones exist.
1. People don't know enough about it to know they are crappy
2. Someone needs a quick iron for a quick job

Currently I am at reason #1.

Reason #2 is a valid one too.
Once I was in another town for a simple maintenance job, and discoverd that I forgot to put a soldering iron in the tool box.
So I went in the town's only hardware store and bough the only soldering iron they had available: a crap 220V/30 W.
Soldering two 5 pin DIN plugs took about 1 hour, doing and redoing  to get a decent result.
From that day I have a soldering kit (JBC adjustable temp stylus + decent solder + 3rd hand) in the car trunk, for any need.

[Sar]

sf?

Sorry, Sparkfun

[thomieboy]

Hello,

I Bought a verry crappy one at a LIDLE store for 20€, and believe me. IT IS REALLY CRAPPY. I learned that you  better pay 50€+ for a solering iron..... 

[lagman]

Is it possible to use sand paper to revive an old soldering tip?
Mine is oxidized and the tin doesn't stick to it...

[Yago]

Is it possible to use sand paper to revive an old soldering tip?
Mine is oxidized and the tin doesn't stick to it...

Not usually .
Sanding it will remove the plating and then the tip will corrode away in no time .
Try getting some brass wool pads , they will removed oxides/crap without taking the plating off too .
The brass wool is better for higher temps too , as the old damp sponge can crack the plating with thermal shock .

[madires]

I Bought a verry crappy one at a LIDLE store for 20€, and believe me. IT IS REALLY CRAPPY. I learned that you  better pay 50€+ for a solering iron..... 

It doesn't need to be one for 50€. An Ersa Multitip costs about 32€ and is a good and solid iron if you don't like to buy a soldering station.