Different types of Soldering Connections | Hagerty DIY

Different types of Soldering Connections | Hagerty DIY


– Hey I’m Matt Lewis with Hagerty. In today’s DIY we’re going to
go in-depth with soldering. Now we do have a few different
options for soldering irons. This is a fairly common
pencil soldering iron that plugs into the wall. Here I’ve got a butane soldering iron that’s super nice to have
if you don’t have power. And then I have a big soldering gun for doing those bigger jobs
that take a lot more heat. And as we’ve seen before,
my two favorite tools for working on wires, your auto
strippers and your crimpers. Most of the time when you’re
simply extending wires or tying into an existing wire, you’re going to want to
use the same size wire from one to the other. So here I’ve got a pair of
16-gauge wires, a blue and a red. And we’re going to go
ahead and take the end off. You want to come back
1/4 inch to 1/2 inch, and give yourself some nice
shiny copper wire as shown. Older cars might have some corrosion; the best way to get solder to stick is have nice shiny wires, so we’re going to want
to take a peek at that. And then finally, personally
I like to take the two, twist them together like this. Make that pre-connection
before you start soldering. So I’ve had my pencil soldering iron warming up for a little wire
here, and I’m going to go ahead and get some solder into these wires. For me, in order to make
sure I get good penetration, I like to heat one side
of the grouping of wires and apply solder to the other; that way I know it’s being pulled through to the soldering iron. And you can watch this copper wire start to turn silver from the solder. And once you see it do that, and you get some good penetration, and it’s shiny and it’s not gloppy, that’s a good way to know that you’ve got a good connection between these wires. And it’s strong. Soldering is a very strong
method to hook wires together. Not that you ever want to
have wires with tension, but you know that’s not
going to break apart with the vibration of a
car running down the road. So there is a little bit
of finesse to soldering. You want to get the wires hot enough to get the solder
penetrated all the way in, but you don’t want it
so hot that you start melting the shielding off of the wire. Now here I’ve got an example of a solder that’s very good and
has great penetration. It’s wrapped all the way around this wire; it’s nice and silver. And on the second one, this
wire that we’re attaching to is quite a bit bigger. A bigger wire’s going
to take longer to heat, and as you can see, we’ve got some good solder happening over here but it never actually got into the middle of this larger wire. That’s not going to be
as good of a connection. You definitely want to
make sure you’re heating it long enough for the solder
to pull in all the way. So a second way you can connect
these two wires together, instead of putting them side by side and twisting the wires
together before we solder, another option is to put them end to end, try to weave the strands together, and then twist so that they’re sort of almost braided or twisted
together and will hold there. The nice thing about this is, when you go to put the
shrink tube over it, it’s a nice smooth transition as opposed to having more or less a
lump that you would get from twisting them, the other way. All right, so like before,
what we’re going to want to do is heat the opposite side of the wires with our soldering iron,
and then feed the solder in. And you can actually see the point it starts to pull into this wiring. Once you have that nice
and pulled through, back off, and your connection’s tight. This wire does cool off pretty good. I mean, it’ll be hot for a minute, so you’re going to want to wait before you put any shrink tube over it. But the solder itself
does harden really quick. So as long as you have enough time before you start moving the wires around, you’re going to be just fine. Now sometimes on a car what you want to do is add into an existing circuit, so let’s pretend that this
wire isn’t cut on either end; it’s running from one place
to another inside the car. You want to add a cigarette lighter, you want to add a radio,
something like that. You don’t want to have to cut
into this wire to solder it, so what you can do is
take the auto strippers, just put it in the middle of the wire, and carefully pull back the housing. Now you have an exposed
piece of wire here. We’ll take our add-on wire, and here I like to pull
back a little additional so I can wrap it around nicely. Get that, and then what you can do is simply wrap this
around the original wire. So we haven’t cut this red wire, but we’re adding onto that
circuit with this blue wire. So now to solder this one, because we know this red wire is thicker,
we’re going to want to apply a little more
heat, again being careful that you’re not melting
all the plastic off. But you have to make sure that
the solder gets penetration. And here we’ll get things started. Now this smaller wire’s
going to pull it in first. So this takes quite a
bit longer to heat up. But once it’s hot enough, you’ll be able to feed the solder into both wires. Now we see that this thicker wire is starting to pull the solder in and the thinner wire has definitely got the solder pulled in. And there you can see,
we have a nice add-on for an existing wire. After this you just want to let it cool, because this wire did get quite warm. And then wrap it with electrical tape. They do make liquid electrical tape but I prefer just regular
electrical tape over it. You can do both if you’re cautious. Now, there is an
alternative to doing this. So something that you’ll often see in fog light kits or
add-on type accessories, are these little guys here, and
they’re called Scotch Locks. I do not advise using these ever. So the way these work, if
you’ve got an existing wire you push it in here, right? You take your new wire, you
shove it in the other one. Then you basically cram
this piece of metal down, cutting into both wires. The issues I have with it,
it’s a very small connection between these two wires, that
the Scotch Lock will make. And it physically cuts into both of them, so if you have the wrong size Scotch Lock, or you’re not careful,
what you can actually do is cut this wire in half or worse, and you’ll lose a lot of the strands that are inside the wire. Everything in a car
vibrates, so little things that are dependent on tiny connections or clamping down and that sort of thing, they just don’t function
as well as soldering. So take your time, solder it, do it right; don’t use this garbage, I hate ’em. I hate ’em (echoing). Now, another connector
that I don’t advise using is something called a wire nut. You see these all the time
homes, which is great; you’ve got a solid core wire,
you’re hooking two together, you put a nut over it. But guess what, your home
doesn’t drive down the street and hit bumps; your car does. So the idea is, you get
your wires twisted together, you take this nut and you just
tighten down over it, right? You’ve got a similar connection
to my original solder here. The problem is, that
thing’s going to vibrate, it’s going to come loose. It’s not a great connection
between the two wires and stranded wires just don’t
work very well under wire nuts in my opinion. So, again, take the time, do it right; use a butt connector,
solder the things together. But avoid Scotch Locks and wire nuts, because I just don’t trust them. Sometimes you’re not going to
be hooking two wires together; what you’re going to be doing is attaching a wire to a terminal. For that instance I’m
going to take this switch and I’m going to solder the wire onto it. As I always do, twist
up the end of this wire. And here we’re going to use
something called tinning, which comes from putting solder
into the end of this wire before we attach it to anything. Solder is again, 60% tin. We’re going to get the end of this wire nice and silver and shiny, full of solder. Let it cool off for a second,
because it’s still quite hot. Now the reason it makes
it a whole lot easier to tin this wire before I
attach to this connector, is the wire is actually going
to hold the solder for me. Also, it keeps the strands
nice and bunched together so while I’m putting it on here, it keeps everything nice and tidy and I’ve already got a reservoir of solder ready to attach to this terminal. So now we’re going to
take our nice tinned wire and attach it to this
terminal here on this switch. What I like to do is put
it through the hole here and then bend it down, so that we’ve got a nice flat piece up against our terminal. Then what we’re going to do is take our nice warm soldering iron, I’m going to heat up our wire, let some additional solder flow in. And attach it right to our terminal. Once that solder cools down,
again what you’re looking for is a nice shiny surface;
you’re not looking for anything globby or cratered. And that’ll tell you that it’s made good attachment to that terminal. So now I’m going to show
an example of a cold solder on this other terminal
using this new wire. Now I’m not going to tin this side; I’m going to go ahead and feed it through, bend it over like I did before. So here we’ve got a good example of, the solder is in the wire, but it didn’t actually connect to the terminal. So this means that terminal
did not get hot enough to absorb the solder
or to melt the solder, which leaves us with a
really bad connection. Sometimes they aren’t quite that loose, but in an automobile
instance you want everything to be really well done, because
they drive down the street, they vibrate, they go over bumps, and that’s why it’s so much more crucial to get really good connections. So even now I’ve added more solder. It appears connected, but
it’s not nearly as nice. Do you see how it’s
kind of bubbled up here, it’s still kind of a ball? If we look at our original
solder you can see it’s nice and cooled on the
terminal that’s well attached. This is a much better attachment, both electrically and for
strength, than this one, which over time I’m sure
if it vibrated enough and spent enough time in a car, would break off and cause you issues. So we’ve covered four different methods of soldering connections: the side by side that I’ve twisted together and soldered; we’ve got an in-line solder; attaching onto an exiting circuit; we’ve got soldering onto a terminal. They all work great,
they’re all nice and strong, they’re going to conduct
electricity just fine. So hopefully that helped you out. If you have comments, leave them below. Hit the subscribe button
to see future videos and we’ll see you next time.

34 thoughts on “Different types of Soldering Connections | Hagerty DIY

  1. "everything in a car vibrates" right..soldering makes the wire hard and brittle near the solder joint. The vibration will make that brittle connection break. That's why manufactures use crimp connections, and never use solder joints.

  2. not the best idea to solder copper with tin, you create a galvanic couple and in a damp environment the connector will rot.

  3. Actually, its better to get the addon through the middle of the main wire, this way it will not bounce off

  4. These are good tips. Butt connectors with built in heat shrink work well to seal up the connection and prevent corrosion.

  5. You know your stuff – great job. As an electronics tech from many years ago I watch an listen very closely. All spot on and correct.

  6. A bunch of old women in the comment section giving their "expert" advise. Clicked on each negative comment username and didn't see one video on soldering. Thought I was looking at the comment section of This Old House where the same seems to be true.

  7. Hey so when you're soldering the wire on that switch tab, isn't that considered a cold solder, even though you've already tinned the wire?

    Would it be bad to heat up the spade on the switch and then add the solder to the top of the wire, granted the two were in contact??

  8. And don't forget, what never use aggressive flux which necessary remove after soldering. It'll kill your connection in future.

  9. Matt: "Scotchlok" is a 3M brand name for a wide variety of devices. The little blue device you showed is correctly called a "tap" connector. I agree, they are NOT intended for automotive wiring. As a 40+ year electrician veteran, I can attest, they aren't that good in building wiring either. I would "disagree" on the "wirenut" critique however. If the "wirenut" is properly sized for the conductors it is joining, it will make a good, lasting, connection since the method used to hold the conductors together is a spring that constantly applies pressure on the joint. Again, correct sizing is critical!! Too small/too big, is where people get into trouble.
    One thing I didn't see you advise or educate on: What type of solder to use/when to use flux???

  10. Great tips. One issue with soldering stranded wires on a vehicle is that it fuses the strands together and prevents the now solid portion from flexing. This causes a stress concentration on the strands at the end of the solder and, under heavy vibration, can fatigue and sever the individual strands. Therefore it's always advisable to add a stress relief or secure hold-down across and just outboard of the connection.

  11. this is the worst way to twist wires ever creates high resistance joint always follow the wire and where possible do not twist together…

  12. PLEASE READ HAGERTY!!!!!!!!!!! Do you think you could rebuild my engine I have a 1970 Ford f100 v8 I really want you guys to rebuild it I am serious. I am 13 years old and this is my third vehicle but it is my favorite!!

  13. terrible soldering video. the iron is bad the fact you dont explain soldering is a form of braze welding.. the fact of heating and not explaining fluxing or heat sinks is bad as well..you can tin wiring with solder pots… so automotive wiring is nightmarish at best due to the lack of proper electrical and electronic principles that are not applied…this is not professional in the least and speaks bad of hagerty.

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