How to Solder Wires Together (Best tips and tricks)

How to Solder Wires Together (Best tips and tricks)

Hey guys, ChrisFix here and today I’m
going to show you the proper way to solder wires together. The process of
soldering is taking two or more wires and joining them together and then using
heat to melt electrical solder connecting those two wires permanently.
When done properly you have a strong conductive connection that turns two
separate wires into one. And learning how to properly solder is a very useful
skill to have. Whether it’s for wiring an LED light bar
like in “Project Nightlight” where I welded up a roof rack and then wired
some bright LED lights on my truck to illuminate the trail both forwards and
in reverse. Or “Project Police Interceptor” where I wired police lights, a siren, dash
camera and other electronics to make a fully functional police car for a police
officer. And looking forward we have the “Driftstang” which is my drift car project
where I’ll be wiring gauges and other goodies into that car, and we’ll also have
“Project Nightlight: Relit” where I’ll be wiring a winch a bunch of off-road lights and
also be fabricating a front and rear bumper at a metal for the truck. And
these two projects are going to require a good amount of soldering so I figured
now is the perfect time to teach you the proper way to solder and the best part
is you don’t need many tools. Here are all the basic tools that you’re gonna need.
You ‘ll need a good soldering gun, flux and solder, a good wire strippers, heat shrink
tubing, a heat gun, safety glasses, and a sponge. Now while these are all the
products that you’re going to need, I’ll also show you some other products that you
might already own and you could use as well. And everything I use in this video
I’ll link in the description so you could find it. And before we begin here
are a few safety tips. Always use safety glasses so if the solder pops or
splashes it won’t get in your eyes. And although it’s common sense soldering
irons get hot, so you don’t want to touch them and you don’t want to lay the tip
down on anything cause it’ll burn. Want to make sure you pay attention to where you’re
soldering and don’t solder near flammable materials and also if you are
soldering inside a car or something you don’t want the hot solder to drip onto
the carpeting and start a fire. So always slide something non-flammable
underneath that if the solder drips down It’ll drip on this instead. Another thing you don’t want to do is
breathe in the smoke from soldering. So make sure you use a fan or work outdoors
in a well-ventilated area. And the final safety concern is most solder has lead in
it and you’re going to be touching the solder so when you finish soldering you
want to clean off your workstation and wash your hands, specially before
handling any food. And with those simple safety precautions in mind let’s get
soldering and soldering is really easy to do and what makes it easy is using
the correct tools. And one of the most important tools is the solder you use.
There are three main types. Leaded solder, lead free solder and silver solder. You
don’t want to use this metalworking silver solder which is designed to
connect metals together like tubing and sheet metal. The other thing is this silver solder
has an acid core it so it’s not meant to be used on wires because over time the
plastic insulation will get eaten away and expose the wire and cause a short. So
that leaves us with lead and lead-free electrical solder. Both of these will
work to solder wires together, and lead free solder is more environmentally
responsible but lead free solder just doesn’t work as well Lead solder is easier to work with
because it soaks into the wire strands better and has a lower melting point so
that’s what I primarily use and I prefer this 60/40 rosin core solder which gives
me the best results and a quick tip just in case you want to know what kind of
solder you have maybe you have unlabeled solder and you don’t know if it’s lead
or lead free solder this is how you could tell. On the left I’m using lead
solder and you could see once it finishes cooling down lead solder has a
shiny look to it. On the right I’m using lead-free solder and once that finishes
cooling down it has an etched or corroded look to it. It’s not shiny. So
that’s a quick tip on how to tell if you’re using leaed or lead free solder. I already mentioned that I like using rosin core solder because the rosin
protects the wires from oxidation but I like to go one step further and use a
rosin paste flux which is another layer of protection from oxidation. When you heat up metals like the wire end you’re going to solder, or even your
soldering iron as the unprotected surface heats up oxides form and coat the
copper and make it really difficult to solder. And it could even create a bad
connection. I use this rosin paste flux which is non-acidic it actually
comes from tree sap and you just coat the wire like that and now the wire is
protected. If you don’t use flux trust me try it out it’s inexpensive and it makes soldering
easier and your soldering job that much better and finally the last important tool that
you’ll need is a soldering iron or soldering gun. Now I like the soldering
iron because when you turn it on it stays on versus pulling the trigger on gun. This is a smaller soldering iron so
it’s really good for smaller gauge wires, nothing thick. It has a narrow tip so
it’s good for working on circuit boards and in really tight places. But when
soldering and cars I prefer using a soldering gun this is a 140 Watt and you
could use this on thinner wires or because it’s more powerful you can even
use it on thicker wires like this. And if you use a soldering gun you’ll know that
you need these specialized tips for and They are about five bucks each so they
could get a little pricey but I have a little trick. What I like to do is I like
to go to my local hardware store and buy this seven strands non insulated
electrical wire, this cost me one dollar and from this big wire you could cut
smaller strands of wire at about five to six inches long and then what you do is
you bend the wire so it’s shaped exactly like your store-bought tip. And
throughout this whole video I’ve been using my homemade tip and they work
great. From one of these strands for a dollar, you can get about 14 tips versus
one of these tips that you buy which is five dollars each. So that’s my quick tip
on saving a bunch of money on making your own tips. And if you’re working
somewhere remote where you don’t have access to electricity, you can get one of
these portable butane torches, and they sell these adapters that go right over
the top which could easily melt solder. So now you know what tools to use for
soldering, I’m going to show you the five simple steps to solder. First you need to
strip the wires, then add your heat shrink tubing, physically connect the wires,
solder the wires together, and then shrink that heat shrink tubing to make a
waterproof connection. Alright, the first step is you need to
strip your wires. You could use an automatic wire stripper like this which,
is actually pretty nice. You just put the wire in, pop it, and the wire is stripped.
These wire strippers are great they’re nice and easy, but personally I like
using one of these old-fashioned wire strippers. So you can see written on the wire
strippers, are the different gauges of wire. I know this is 12 gauge so you just
slide that into 12 and you want to have about the same amount of length stripped
of each wire which will make connecting them easier. Now just squeeze down on the
strippers and twist back and forth a few times. And then while squeezing pull the
insulation off, and that’s all there is to it. And one thing to be careful of
while stripping wires, is breaking the strands off the wire. Even though it
seems insignificant if you remove only a few strands that could increase
the resistance and heat up the wire in that area and if a fuse doesn’t blow, the
wire could melt and cause a fire. So if you break any strands by mistake,
just cut the wire and re-strip it so you don’t have any strands missing. Αll
right, with the wire end stripped, we can move on to step two. For step two you’re gonna grab your heat shrink. I
like having a kit like this. It has bunch of different sizes and colors and when
picking your heat shrink you want to try to find the thinnest heat shrink that
will fit over your wires. The really wide heat shrink like this, that has a lot of
space around the wire, isn’t going to shrink enough to seal the wire. So that’s
not going to work. You want something like this, which just
barely fits over the wire and when this gets heated up, it’ll shrink nice and
tight. Now make sure you have enough heat shrink to cover part of the insulation
and all the exposed wire. And don’t forget to slide your heat shrink down
the wire and slide away from the area that you’re gonna be soldering, because
the heat generated from soldering could actually shrink the tube. Now for the
third step we’re going to connect these wires and there’s a few different ways
you could do it. I have two ways that I use all the time and they pretty much
cover every situation. The first method is get these two ends
and unravel all the strands, spread them apart a little bit just like that, and you’re
going to want to do that on both sides. Now you’re going to intermesh these two
strands together like that and then you’re going to twist. So that’s the
first method, intermesh the strands twist them together, and it looks just like
this. The second splice I want to show you is called alignments splice or western
union splice. Make sure you have enough wire stripped and twist those strands
tight. Then make an X and spin one wire around the other wire and just keep
spinning each wire around the other as tight and neat as you can until you run
out of wire to twist. You don’t want the copper strands to stick out, so make sure
you tuck the ends in so they’re flushed with the wire. Copper strand sticking out
could pierce the heat shrink and then cause a short. Now which splice should you
use? Well they both work great so try each
one and see what you like. With the wire spliced together, you want to use a
helping hands which holds the wire steady for when you solder. Now a quick tip is I
cover the end of the alligator clips with heat shrink tubing because the bare
alligator clips are sharp and cut through the wire insulation exposing
bare wire. Now use the helping hands to hold the wires in place and we’re ready
to add our solder. First rub the rosin flux into the wire. Get it all over the wires because this
is going to help the solder flow into the wires. Then you’re gonna grab your
soldering gun and heat it up by holding the trigger down. As it heats up use a
damp sponge to wipe the tip and remove all the oxidation. You see how the tip is
tined and I just removed all that oxidation is nice and shiny now that’s
what you want to see. Now in this case my soldering tip is already tined but if your tip is bare you’re going to
want to tin it. So heat the tip up and just add a little bit of solder to cover
the tip. Then wipe off the tip on a damp sponge to remove all but a thin layer of
solder, which is going to help the tip last longer and it’s also going to help
speed up the heat transfer from the tip to the wires. Now is the most important part.
We need to heat up the copper wire using our soldering gun. So place the tip of
the soldering gun underneath the wire and feed just a little bit of solder in
between the tip and the wire. This solder is going to melt against the tip and
wire so it’s going to speed up the heat transfer between the tip and the wire.
Thicker wires do take a little bit longer to heat up but after a few
seconds you should be ready to add solder. You want to add the solder at the
top of the wire. You don’t want to touch the solder to the tip. You feed the
solder into the copper strands and let the solder wick through the strands. You
don’t need a lot of solder either, just enough so that the strands are coated. You
don’t want blobs of solder. Once you added enough solder remove the soldering gun
and let the joint cool. Don’t touch the joint until it’s
completely cool because if you touch the joint it will move the wires around
while the solder is still in a liquid form and that could create cracks in the
solder or air gaps, so your connection won’t be as good. After every time you
solder, with the soldering tip still hot you want to clean it off by wiping it
against a damp sponge. You want to do this so you have a clean tip every time you
go to solder. And now with the wires cooled down, inspect your soldering job. You
want to see the solder wick completely through the wires. You want the outline
of the strands to be visible but you don’t want to see any bare copper. Also
you don’t want to see large globes of solder, because that indicates there
could be a cold solder. But what we’re looking at here is a perfect example of
a correctly soldered wire. Alright with a good soldered connection now we’re on
our last step, step 5 and what we’re gonna do is we’re gonna
take our heat shrink and we’re going to pull it up to are soldered area. But
before we slide it over the area that we just soldered I have a quick tip
that’s going to make this connection last even longer and make it waterproof. And that’s using
silicone paste or dielectric grease. All you have to do is get some silicone on
there and then slide the heat shrink tubing over the top just like that. So now you want to heat the shrink tubing
with either a heat gun or a lighter and you want to start heating it from the
middle and move outwards. And this is going to force any extra silicon
outwards. Now silicone or dielectric grease is perfect because it prevents
moisture and it’s also an electrical insulator. You can see it getting pushed
right out and there you go. Look at that!! We just created a waterproof seal
that’ll last a long time and the last thing I want to mention is one of the
most common mistakes I see people make when they solder, and it’s called a cold
solder. You never want to touch the solder to tip of the iron and drip it on
to the wires. The solder doesn’t penetrate and it makes for a very poor
connection. Always add your heat to the bottom of the wire and add your solder
at the top of the wire ,so the solder melts into the wire. And with that, now
you know how to properly solder, so go practice on some wires. As always the
products I used in this video are linked in the description so you could easily
find them. Hopefully the video was helpful and if you solder something
for one of your projects make sure you follow me on Instagram and Facebook and send
me a picture of your work. And if you aren’t subscribed to my channel consider subscribing for more videos
just like this. I’ll be using this process on many new projects so stay


  1. Always wash your hands with cold water after working with heavy metals, because it will cause your pores to contract, making it harder for the particles to get into your system. Also, if you work with them enough, you may want to invest in de-lead wipes or soap, both of which do a fantastic job.

  2. Using lead-free solder, working on circuit boards and very thin wires. I can't manage to solder anything, the solder sticks to the soldering gun (stick) but it never attaches to copper wires…never. I am using flux, I am cleaning the tip, but the solder never sticks to the goddamn wires or circuit contacts. i've burned through a lot of stuff, and never managed to fix anything (from Led bulbs, to USB drives)…

  3. The second method is the style that NASA teaches Astronauts. Strip at least an inch back, pre-tin the wires, bend 90° two-thirds of the way back on the stripped section, twist the wires around a minimum 3 times on each side, now solder the wires.
    The goal isn't just a good electrical connection, it's a solid mechanical connection that doesn't have weak spots around the solder joint.

  4. I wasn't going to comment, besides, no one is going to see this on a 3 year old video, but people who think lead free or 'green' products are better for the environment need to reconsider the facts. Fact: It takes almost 6 times more 'green' paint to get the same results as 'regular' paint. That means 6 times more energy used for production, 6 times more trucks on the highway to transport all that sweet, 'green' paint to market, 6 times longer to do the job, etc., etc., etc. Fact: RoHS complaint (lead free) solder (say colder with an s at the front instead of a hard c sound) leads to poor component performance, dim or non-functional displays, shorted boards when connections over-amp or simple failure due to no connection. (See videos on 2003-2008 Corolla clock dim/unlit.) The environmental impact of mining the precious metals used on electronic components alone means that the more reliable the component the 'greener' the component. If your solder is the weak link, you're basically taking a dump on your own environmental concerns. In 40 years, I've never seen a more optimum electronics/electrical solder blend than 63/37 (tin/lead) solder. Low melting point (less likelihood of component damage), greater flowability, less material needed, less energy used heating the iron, reduced fumes, best joints all around. End of rant. As for this video, par excellence! As usual, Chris Fix does a great tutorial and is one of my first go-to experts when I want to do any work on my vehicles. Great video!

  5. Best information I have seen on this! I wondered about the dielectric grease but doing it the way you showed just made so much sense!! Well done

  6. I just took a course for high reliably soldering (NASA Standards). Soooo much attention to detail in that class. Soldering will never be the same… This isn't bad for the average person though.

  7. Anyone can help me please… Because my soldering iron give me shock whenever i touch it (through soldering material) during soldering…

  8. I do a lot of soldering. I was thinking when your vid came up, what can this dude teach me, nothing, I know what I'm doing, then you did the lead and lead-free comparison. 👍 awesome thanks……. Have you tried the new-ish heat shrink solder joint, put the clear heat shrink on and it has a ring of solder in the middle, heat it all up with a lighter and it solders and heat shrinks all in one go. Good for a quick job….. Great vid mate……

  9. I have never done this before but I watch all your videos and this is going to help a lot when I go through my wiring on my rally car project

  10. Chris, I cannot think of a suggestion. Perfect! Actually, I am going to heat shrink tubing over my "helping hands",. Excellent as usual!

  11. Great video, but let me toss out a caution about ordering. The soldering gun shown is currently unavailable at Amazon, even though their website will show it is. I tried to order twice, and both times the sellers sent me a newer, cheaper, and less well-reviewed model. Oh, and neither seller offered to make up the difference between the price of the original order and the one they sent. And, of course, both made the return difficult.

  12. I bet you could talk a scared cat into water. I've watched so many videos and thank god yours came on here you can teach brother. I give you that. If you ever need to learn how to do anything ill show you a video of you doing it lmao.

  13. Verry nice video, one thing i would recommend is to not use to much heat. Also dont heat the copper to much, you can see the isolation started to melt, this will cause it to get more brittle and crack over time.

  14. Pro tip: use a larger piece of bigger diameter hear shrink to shrink over the first piece. It makes the connection more secure from intrusion.

  15. im 15 really poor and i need to fix some wires soo i tried the duct tape trick because cheaper and it exploded now im gonna try this hope i do it right

  16. Thanks for the video. Just replaced a bunch of bad wires on my surround sound speakers. No joke I did the solder on the tip of the iron thing lol. It's a lil globby and not that pretty but hey it works. I wish I would have watched this video first before trying it. This video makes sense and is filmed perfectly. Thanks for education me.

  17. 10:25 Wrong, dont clean tip after use (only before), solder normaly prevent oxidation of tip, if you remove that layer tip ll burn out quicker.

    8:35 If you dont have helping hands, just band tin streight and then solder the wire.

  18. Excellent tips on soldering electrical wires,very helpful information indeed. I just had to give this video a thumbs up.

    😃Would you recommend the same soldering steps on silicone wires?

  19. We give the Americans our language and what do they do? They go and butcher words like maths and colour and then completely lose the "L" in solder.

  20. Watched many videos of this type today… this is the best one and the first one that gave me confidence to try it out myself = made it look as easy as possible. GJ

  21. Chris, you have the most efficient, easy-to-understand "how-to" videos. If you are not already, you would make a GREAT teacher!

  22. Take a look at a book called automotive wiring and electrical systems by tony candela. It’s on amazon and offers A LOT of tips on every electrical situation you may find yourself in, as well as tools to have on hand. With splicing copper, not that your doing it wrong but IMO your adding a lot of unnecessary steps for such a rudimentary straight splice. I highly recommend the book.

  23. exelent tutorial, i'm an industrial electrician and also work with electronics, everithing was very well explained, i would just add that if you are gonna solder on an old wire, you want to clean the cooper first because even being insulated, wen you strip the tip of the wire it comes out filty, so with paint thinner, break cleaner or contact cleaner remove grease and other contaminants from the bare cooper, there is also a very good paste i use that clean the surface and acts as a flux when heated, is burley brand paste, comes in a yellow thin can with red vintage font, also if you wanna make an electical connection that will be subject to high current is a better pratice to crimp the connections, the solder joint has a little resistant that can produce heat and gets brittle over time

  24. I loathe those soldering "guns". 90% of the heat is in the rest of the wire and in the body. 140W used to get a 15W equivalent tip. Especially when you make your own tip out of copper wire. The entire wire is heating up.

  25. does a soldered wire say like a 14 gauge wire for your car need to be dunked in baking soda water mix after soldering?I had to d this when making large battery cables after dipping them in a melted lead tin solder to nutralize acids I think it was,Let me know if this is needed to be done for little automotive soldering wires and thanks.

  26. Ok, why is it every single solderer I've ever seen on youtube neglects to clean off the flux? Flux is Corrosive! Otherwise A+ vid.

  27. Has Chris ever made a bad tutorial? This is honestly the best tutorial on the subject I've seen. And I've seen many over my career.

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