Soldering without a soldering iron

Originally published at:


I’m soldering right now.


It may be intuitively appealing, but I don’t think it’s at all clear that these joints are better than good crimped joints. If you want your crimped joints to be watertight, you can always put double-walled heat shrink which is lined with adhesive over the crimp (and you can get crimped butt splices with heat shrink built in) – although really, 95% of your wiring shouldn’t need that extra protection.

In industry, where engineers actually analyze failures, soldering is reserved for specific scenarios and avoided in cabling and free hanging wires. Wiring in harsh industrial settings on highly reliable machinery where no expense need be spared? All crimped. My father is an electrician who builds and repairs heavy machinery for marine environments, with service life measured in decades. He’s also an old audiophile and loves a perfect solder joint done with good old 60/40 solder, but when he’s doing housewiring, building machines for work, or working on a car, he goes with crimped connectors or wire nuts.

Soldered joints are brittle, and fail in a variety of entertaining ways over the long term in harsh environments. Especially with low temperature solder, just in my hobby projects I’ve personally had a lot of trouble with the joints not being mechanically strong – I can pull them apart with my hands easily. Here’s a better discussion of it than I can offer though:


What’s wrong with zip ties and a couple coats of shielded techflex?


The close up on the face using wide angle lens (?) is kinda creepy.

Ive actually used these, and they are neat, but when you heat them you have to hold the wires very steady, because the plastic becomes very pliable. The ones we tried were the amazon lowest price at the time, and the solder was total garbage. If we got more expensive ones maybe some of those gripes would be mitigated.

For my hobbyist projects when i need a splice or tap I like these guys


Butt connectors with solder have been around for a long time, and in theory give you both the strength of the mechanical connection and the conductivity of the solder joint. The problem with these connections is that they are relatively low-temperature, which means you can’t use them where you’d most want to, eg under the hood of your car or inside your espresso machine.


I’d be soldering right now if I had my stuff with me.

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Back in the '90s we called them solder sleeves, and they were very reliable. Cray computers used thousands of them.


Yeah, I remember in the early 90’s I got a sample of some from a vendor and, while I saw the utility of them, I didn’t have a particular need for them. I was working for an appliance OEM and we would haver have used anything but a crimped connection in a product. Solder was for holding parts on a board and providing a good electrical connection for parts on PCBs.

Compression is the gold standard, but there’s something to be said for the convenience of these parts. They give you a solder joint, a shrink wrap, and a glue seal for watertightness. That’s a lot of benefit. But, as has been pointed out, it’s not as good as a crimped connection and the solder is much lower temp than even normal solder, so the connections are not good in hot environments nor at higher currents. But for signal lines at normal room temperature? They’re super covenient.

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Not saying they don’t have their use, or that when used properly they won’t last. Just keep in mind that a sealed, stationary supercomputer in a temperature and humidity controlled room is not exactly the most challenging environment.

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I’m holding out for a way to solder components to a circuit board without a soldering iron.

Uhhhhhhh… what?

It’s impossible as far as I know. But I can dream, can’t I?

ETA: Oh, I wrote “with”, not “without”. My bad. Fixed.

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(breathes out) Okay, better, thank you.

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Doing this as a separate reply to keep the threading sane.

Have you heard about solder paste and hot air soldering? It’s great for SMD, but can work for through hole as well–though not as nicely.


I’ve used solder paste, but with an iron—was I doing it wrong? I’ve never heard of hot air soldering, though. I’ll look into it!


Just wait for @nixiebunny to come into this thread and explain all the ways you can do this.

No that’s linear FOV, and I only do it because my apartment doesn’t afford a wider clean background angle. FWIW, I think the choice to hide behind an alias instead of using your real name is a bit creepy.

Thanks for this comment; I spent a lot of time trying to figure out how old this idea was, without finding a definitive answer. Knowing that they were around in the 1990s is an extremely informative data point.