I’ve recently gotten into simple electronics with Arduino or Raspberry at a hobbyist level. I’ve (even more) recently noticed a number of YouTube videos like where they build cool little gadgets by soldering components directly together instead of hooking everything to a circuit board. It looks like it could be fun to try, but I don’t get how the solder is working. It’s like it appears by magic. Possibly some solder is on the iron itself, but in my limited understanding, it seems like that would make cold solder joints.
One important thing to do is to put flux on the leads where you are soldering. Then you can apply a blob of solder to the iron and heat the joint and the solder should flow into it. If you do that without pre-fluxing the leads, the flux will boil out of the solder on the iron and the connection will be hard to make.
For heat sensitive components be careful as there is no board to act as a bit of a heat sink.
I don’t particularly enjoy this style of soldering. Keeping the pieces aligned and the wires properly connected while trying to apply solder can be a pain. You’ll want a set of helping hands or other clamps/vises to help you with that. One thing you can do to make it easier is to pre-tin the areas on the leads where the connection will be.
I’ve been soldering electronics since 1977. I use 63/37 rosin core solder. 60/40 works almost as well. I’ve never use flux. (It’s already in the solder.)
I’ve watched a few YT videos on soldering. I use a somewhat different technique than most videos. I really should make a video some day to show what works for me.
This is called “dead bug” construction. It is hard to see in the video exactly what he or she is doing, but, believe me, it is not magic, and you do need to buy solder The wires and/or the tip or the iron are tinned with a small amount of solder before attachment (flux can help with this, but as @Crafter_Man points out there is already a bunch in the solder wire) though this step is not shown in the video—some of the time you can see solder on the ends of the wires though. In any case, in order to refine your technique I would practice a little bit on some cheap circuits before soldering anything expensive. (An 8-bit micro-controller is only about a $1.20, but why fry them)
I noticed that at 1.17 on the video he clips excess lead and it appears to me that the wires move in relation to one another. Not enough solder. I’m suer he fixed that, but left it out of the video.
Watch a bunch of YT videos. But… soldering is a bit of an art.
At work I guess I’m sort of the “go to” person on soldering. I’ve tried showing others on how to do it, but I think it ultimately comes down to self-learning. You eventually learn what works for you.
There are also IPC courses on it. They’re good. But I do things a bit differently.
Yeah, I would never solder in the manner the video shows. It relies on a bit of residual solder on the iron and that the leads are pre-tinned. I would always tin the wires at the joint myself with enough solder to know the joint will be good and only use the iron to reflow the solder, not deliver solder when making the joint. As @GaryM notes, at 1:17 a joint fails when the lead is clipped.
Relying on the tinning on the leads is fine when using a printed circuit board and there is enough time to deliver solder to the joint properly. But just relying on a small blob of solder on the iron to wick into the joint like this is asking for trouble. I’m sure we have all done it. But it isn’t good practice.It is too easy to end up with with a cold joint or in the case of a hard wired construction like this, mechanical failure.
I didn’t get into straight flux until somewhat recently. We hired a former mil tech who was big into flux and, I confess, he really turned me on to the stuff. When you have a lead or wire that just won’t wet, a quick dip into the flux takes are of it all. The flux inside the solder works for most applications but I’ve run into those times where it isn’t enough.
Alright, you got me curious, let’s see it.
(Please don’t tell the boss but …) I love soldering. It’s really satisfying to use as little as possible extra around the work, not burning the substrate and to make it all look pretty. As said, flowing it across wires in a connector’s solder cup is very … pleasant(?) and I know the joint will last a very long time.
As mentioned, I’m now 53 and have been soldering since I’ve been 10. The flux in the solder is all I’ve ever needed. I guess I’ve just learned an efficient technique to soldering. I really need to make some YT videos.
When I started soldering, I’d watch guys do exactly what they were doing in the video but learnt very soon that what they were doing destroyed Ics.
So if you are doing transistors and diodes, then the method without a PCB or a simple board works great, but if you want complex electronics then it’s worthwhile to invent in a PCB.
Also a good iron with variable power matters.
Invest in a good soldering iron if possible.
If God had meant for us to solder, he would have given us four hands.
But seriously, I’ve always been taught that you should never depend on solder for mechanical strength: You should do something else, like twisting the wires together, for that. The solder is just to provide an electrical connection.
Now, that’s not an absolute rule (very few rules are), especially for something that needs only trivial amounts of strength, like some of these projects. But I still see no reason not to twist the wires together.
Modern PCBs contain surface mount devices (SMDs). And for the vast majority of SMDs, the solder functions as a mechanical connection as well as an electrical connection. Having said that, a solder junction is indeed significantly weaker compared to nearly all other fastening techniques (e.g. brazing, welding, threaded bolt). It’s strong enough to hold small components on a board, but that’s about it.
It’s extruded with a die, but much larger diameter than the final solder wire, then reduced with reducing dies or rollers. I saw it on one of those How It’s Made-style TV shows.
A surface-mount device is basically holes that you poke the leads of the components through, right? That would, in itself, add a non-negligible amount of strength: You can pick up (and tilt, and maybe even invert) such a board with the components mounted (but not yet soldered) without the components flying all over the place.
It’s like the best way to get to Carnegie Hall: Practice, man practice.
When dinosaurs roamed the earth and I was working for a military contractor, I watched one of the engineers trying to solder up a home job. After a couple minutes I couldn’t stand his dabbing away any more and said, “Gimmie dat!” and finished it up in a quarter the time I’d been watching him and neater as well.
As I handed it to him he said, “You guys are so good at this.”
I replied, “We can’t get along on just brains so we have to develop skills, and anyway, if you think I’m good, you should watch the rework ladies a while.”
The wires and/or the tip or the iron are tinned with a small amount of solder before attachment (flux can help with this, but as 