Finessing A Soldering Iron To Remove Large Connectors

March 17, 2023 by Bryan Cockfield 32 Comments

One of the first tools that is added to a toolbox when working on electronics, perhaps besides a multimeter, is a soldering iron. From there, soldering tools can be added as needed such as a hot air gun, reflow oven, soldering gun, or desoldering pump. But often a soldering iron is all that’s needed even for some specialized tasks as [Mr SolderFix] demonstrates.

This specific technique involves removing a large connector from a PCB. Typically either a heat gun would be used, which might damage the PCB, or a tedious process involving a desoldering tool or braided wick might be tried. But with just a soldering iron, a few pieces of wire can be soldered around each of the pins to create a massive solder blob which connects all the pins of the connector to this wire. With everything connected to solder and wire, the soldering iron is simply pressed into this amalgamation and the connector will fall right out of the board, and the wire can simply be dropped away from the PCB along with most of the solder.

There is some cleanup work to do afterwards, especially removing excess solder in the holes in the PCB, but it’s nothing a little wick and effort can’t take care of. Compared to other methods which might require specialized tools or a lot more time, this is quite the technique to add to one’s soldering repertoire. For some more advanced desoldering techniques, take a look at this method for saving PCBs from some thermal stresses.

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Solder Pot From The Kitchen

April 5, 2022 by Al Williams 15 Comments

We aren’t shy of dangerous projects, but, then again, a large cooking pan full of lead solder might be a bit much, even for us. It goes without saying that you should be extremely careful and you won’t want to use any of the cookware again for any other purpose. You can see the build in the video below.

On the one hand, it isn’t hard to make a solder pot. All you need is a container that won’t melt and a heat source. But it seems like molten metal should be in something a little harder to tip over. The real story here is the technique for using the solder pot as the build is dead simple: a cheap hot plate and an iron skillet are all it takes.

Why do you want a solder pot? They are useful. As [Coalpeck] shows, you can use them to dip solder a through hole PCB easily enough. They are great, too, if you want to tin a lot of wires. They also can do a great job of removing parts from a board or a connector. Check out the old, but good video of a commercial unit removing a PCB connector after the main video.

We thought the temperature measurement technique of letting newspaper turn brown was interesting. Granted, a commercial solder pot big enough to be useful isn’t cheap. You can, though, get smaller pots (50-80 mm) for under $50. These will usually have a tray to catch spills and will be harder to tip over by accident. Not that you won’t want to be careful, though. If you do attempt this, we suggest you use a pan with no handle and set it in an outer pan to catch any overflow. But if you spill a few pounds of molten solder on your workbench, don’t say we didn’t warn you.

We’ve covered several homebrew solder pots over the years but, mysteriously, all the original websites are gone. We hope they are OK. We did look at a host of desoldering techniques that include the solder pot. Or ditch the pot of hot lead and try one of [Bil Herd]’s methods.

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Soldering iron tip heating up a piece of wire wrapped around the metal parts of a MicroUSB socket, with melted solder heating up all the important parts.

Desoldering Without Hot Air: Piece Of Wire Edition

March 1, 2022 by Arya Voronova 8 Comments

Quite a few hackers nowadays share their tips and tricks on Twitter – it’s easy to do so, and provided either an existing audience or a bit of effort to get one, you’ll get at least a few notifications telling you that people appreciated what you had to share. Today, we’re covering two desoldering hacks highlighted there that will be useful some day, exactly when you need them. Both of them use a piece of wire and, in a way, extend the reach of your soldering iron’s tip. Copper wire would work better because of superior thermal conductivity, but other types of solid core wire will work in a pinch.

First hack is brought to us by [Erin Rose] – desoldering a microUSB socket. You need to heat up the entire shield and the pins at the same time, which the wire acts as a thermal gateway for. As long as there are melted solder bridges from sections of the wire to all the copper-to-part connection points, it should be easy to pump enough heat into the solder joints for all of them to eventually melt and give in at once.

Second hack is brought to us by [arturo182]. A piece of thick wire acts, again, as a heat conductor to desolder a 0.5mm pitch TQFP-100 package IC. You have to bend the wire into a correct shape, so that it’s as close to the pins of the TQFP as possible. In this situation, the wire performs two functions: first, transferring the heat from the iron’s tip to different points along the wire, then, as a barrier that helps solder not escape too far away from the pins. Copious amounts of flux likely desired for this one!

Hopefully, this comes handy if you ever need to replace an all-SMD part ASAP but don’t have a hot air gun or a hotplate handy. After getting this concept down to an art, we are sure you won’t limit yourself to TQFP parts and MicroUSB sockets. We’ve talked about desoldering practices before as part of our newsletter, and using lots of melted solder for part removal is not a foreign concept to us, either.

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Solder Bridges Aid Desoldering

July 24, 2021 by Al Williams 24 Comments

As our own Elliot Williams laid out, many people think that soldering is a key skill for electronics, but we don’t as often think about desoldering. Even if you are perfect in your technique, there’s always the chance you’ll put in a bad part or have a part fail later and it will need replacement. [Robert] has a short video showing his method for removing through-hole components and you can see it below.

This isn’t the first time we’ve seen it, of course. In fact, it is very much like using hot air, although it doesn’t require hot air, just extra solder and a regular iron. Of course, if we knew that connector was bad, we’d have been tempted to cut each pin apart and remove them one at a time. Heating a joint and then slamming your hand on the bench can work wonders.

We always think desoldering pumps are a good idea, but the electric ones tend to be anemic. The ones with the springs are usually better, but still have limitations. In the end, we’ll stick with using hot air, but if all you have is an iron, this method is worth checking out. You might also be interested in the needle method.

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Learning To Desolder Gracefully

July 24, 2021 by Elliot Williams 45 Comments

When you’re just learning to sketch, you use graphite. Why? It’s cheap, great at training you to recognize different shades, and most of all, it’s erasable. When you’re learning, you’re going to make mistakes, and un-making them is an important part of the game. Same goes for electronics, of course, so when you’re teaching someone to solder, don’t neglect teaching them to desolder.

We could argue all day about the best ways of pressing the molten-metal undo button, but the truth is that it’s horses for courses. I’ve had really good luck with solder braid and maybe a little heat gun to pull up reluctant SOIC surface-mount chips, but nothing beats a solder sucker for clearing out a few through-holes. (I haven’t tried the questionable, but time-tested practice of blasting the joint with compressed air.)

For bulk part removal, all you really have to do is heat the board up, and there’s plenty of ways to do that, ranging from fancy to foolish. Low-temperature alloys help out in really tough cases. And for removing rows of pinheaders, it can help to add more solder along the row until it’s one molten blob, and then tap the PCB and watch the part — and hot liquid metal! — just drop out.

But the bigger point is that an important step in learning a new technique is learning to undo your mistakes. It makes it all a lot less intimidating when you know that you can just pull out the solder braid and call “do-over”. And don’t forget the flux.

Extreme Refurbishing: Amiga Edition

October 11, 2019 by Bryan Cockfield 17 Comments

The last Amiga personal computer rolled off the assembly line in 1996, well over 20 years ago. Of course, they had their real heyday in the late 80s, so obviously if you have any around now they’ll be in need of a little bit of attention. [Drygol] recently received what looks like a pallet of old Amiga parts and set about building this special one: The Vampiric Amiga A500.

The foundation of this project was a plain A500 with quite a bit of damage. Corrosion and rust abounded inside the case, as well as at least one animal. To start the refurbishment, the first step was to remove the rust from the case and shields by an electrochemical method. From there, he turned his attention to the motherboard and removed all of the chips and started cleaning. Some of the connectors had to be desoldered and bathed in phosphoric acid to remove rust and corrosion, and once everything was put back together it looks almost brand new.

Of course, some other repairs had to be made to the keyboard and [Drygol] put a unique paint job on the exterior of this build (and gave it a name to match), but it’s a perfect working Amiga with original hardware, ready to go for any retrocomputing enthusiast. He’s no stranger around here, either; he did another extreme restoration of an Atari 800 XL about a year ago.

Review: Shi Yi Tool Sy365-8 Desoldering Iron, Second Cheapest You Can Find

July 15, 2019 by Jenny List 21 Comments

Is the second cheapest tool you can find any better than the cheapest one?

Readers with long memories will recall there was a time when I amused myself by tacking inexpensive tools or electronic devices to my various orders from the Chinese electronic Aladdin’s Cave. Often these inexpensive purchases proved to be as disastrous or ineffective as you might expect, but sometimes they show unexpected promise, true diamonds in the rough. It’s been a while and life has intervened over the last year, but it’s time to resume this harmless diversion.

Memories Of An Explosive Conclusion

A particularly memorable review came in April 2018, when I bought a five pound ($6.30) desoldering iron. I described it then as an “unholy lovechild of a cheap solder sucker and an even cheaper soldering iron“, and while that was an accurate portrayal it also showed promise as a useful tool that would fill a niche in my requirements. Desoldering is always slightly annoying, and a heated desolder pump genuinely does make a difference. Unfortunately for me, the cheap desoldering tool was not a product I’d recommend that anyone try for themselves. A combination of questionable electrical safety and a propensity to explosively deconstruct itself meant it has languished unused in my big box of cheap junk, and I’m still without a decent desoldering solution. It is time to buy something better, and in the rich tradition of reviewing inexpensive stuff I decided to pick up the next cheapest desoldering iron I could find. Eight pounds ($10) secured me a Shi Yi Tool Sy365-8, and I set to on this review. Continue reading “Review: Shi Yi Tool Sy365-8 Desoldering Iron, Second Cheapest You Can Find” →