How To Solder – DIY, Cars, Electronics, Boats, Solar, …
There are a lot of projects that require some
basic soldering skills. Joining of wires and such.
Including things like working on electronics, cars, boats, boat trailers, solar projects….
where you want a good, low resistance connection. Water proof, mechanically strong.
Other things include drip systems and low voltage yard lighting.
Soldering is not difficult. I have been doing it since I was 5 years old.
I’ve learned a lot from books and from experience. Let me show you some of those things.
Today I will be working with this bigger soldering gun.
It is easier for you to see. I can use bigger wires and it’s a lot easier to see.
The same rules will apply to smaller soldering guns and soldering pencils.
First thing to good soldering is to have rosin core solder.
Non-corrosive. 60/40 tin lead is pretty standard. Never, ever, ever use acid core solder or
acid flux on anything electrical or electronic. Because it will get into the works and corrode
things for years to come. Rosin core solder, non-corrosive.
The main secret of good soldering is CLEAN. Starting with a clean tip on your soldering
iron. Having good clean work.
This is not clean. This is absolutely wrong! You do not want to try to solder stuff like
this. You want clean, shiny copper colored work.
And 1 thing that people don’t talk about is you want clean solder.
You can see down here this is dull grey and up here it’s more shiny.
This has been sitting around a while and it picked up oxide.
Oil is the absolute worst thing. Oil from dirty hands. Like these.
Oil gets on your solder and oil will ruin a solder joint quicker than anything.
Good clean solder. Before you begin, dampen your soldering sponge.
Definitely use a soldering sponge. If you don’t have a soldering sponge, use
a damp paper towel. Don’t sling your solder around. Use this to
clean your tip. Solder is toxic. Slinging it around is a bad
idea. Clean your solder. Wipe it off. Make sure
there is no oil or grease on it. Make sure there’s no oxide layer on it.
Clean solder is also important. There are 4 steps to good soldering:
1) Have a good clean joint. Mechanically sound and clean.
See right here? This is not clean. I am going to go and cut this out of there and re-prepare
this and I will be right back. We have our good clean joint. Now we want
to make it mechanically sound. We will just twist it together.
Use pliers if you need to. This is a stout wire so I will use my pliers on it.
Twist it together. There we are.
You want it strong enough that it will not come apart when you are soldering it.
2) Have a clean soldering tip. Clean it off on your soldering sponge.
Get it nice and shiny. If it’s not shiny, add some solder to it.
Let me go over the third and fourth steps first because they go pretty quickly.
The 3rd step is to press the soldering iron firmly on to the work and then wet the tip
a little with some solder. This solder is not meant to start the soldering process.
What it does it help transfer heat from the tip to the work.
The fourth step is to apply heat and apply solder to the work.
You apply solder to the work. If you apply solder to the tip the flux will burn away
before it’s had time to do the job with the copper.
Then you move these 2 together, the tip and solder.
When you are done, lift them away. Do not touch the work piece until it has had
time to cool. If you move a joint while it is still liquid
the joint will be a “cold” joint and it will not be strong / good.
Here we go. Touch the soldering iron on to the work.
Add a little solder to help wet the tip and help transfer heat.
Then I am going to move the solder and soldering iron along the work.
And that’s it. Now I will let it sit until it cools.
Let’s inspect our joint. It’s shiny. The solder is consistent. It has
soaked into the wire. It’s consistent all the way around.
So it’s a good, clean mechanically and electrically sound joint.
Trimmed off the edge. Make sure there’s no sharp points.
It’s ready to tape or shrinkwrap. Let’s try soldering some wires that are not
clean and see what happens. See how the solder balls up on there?
It does not try to stick to it? As I move along, it’s not doing anything.
It does not want to stick. If I apply enough solder / flux sooner or
later the flux will eat through the oxide. But that’s not going to make a good joint. Let’s look at what we just did.
That’s a very weak joint. You notice the solder did not really bond
to the second wire? With enough flux you can eat through the oxide
coating on the wire, but it’s a huge waste of solder and time.
And you usually end up with a bad joint like this one.
Before you put all your soldering stuff away. You should notice that, this is a piece of
solder, if you look at the end of it there’s a hole in it.
Solder is actually a tube and in the center of it is that flux we talk about.
Before you put your solder away, pinch the end of it so that the flux does not leak out
while it is sitting. Otherwise you will end up with a roll of ruined solder. Let’s talk about some minimal soldering safety.
First solder contains lead. Lead is a neurotoxin. It is not good stuff.
If you solder occasionally, it is not considered high risk.
If you do a lot of soldering you should definitely looking into serious safety precautions.
Again these are the basics for home / hobby soldering.
You never want to use this type of solder for food, preparing cups, cooking utensils,
anything like that. Because it does contain lead. It will get into food / drink.
You always want to solder where there is good air flow.
The fumes are bad for you. I’ve got a fan over here and a ceiling fan
up here blowing down. You never, ever want to flip off solder. Everyone
says, “just flip off the excess solder”. That’s a really bad idea.
First it leaves solder droplets around like this. Kids and pets can find that shiny piece
of metal and pick it up, put it in their mouths, whatever. It’s not good.
Also, if you scatter solder around a house or workplace you can end up with lead contamination.
That’s really hard to re-mediate. And you can find selling the property becomes really
difficult, if you have lead contamination. Don’t do that.
If you need to get rid of excess solder, what I suggest is just a quick touch to your solder
sponge. Or you can make one of these, a solder tray,
and you can flip it in there. It can be recycled. Along those same lines, keep your hands clean.
You don’t want to transfer lead from your solder and your work area into your mouth,
eyes, whatever. Soldering is at high temperature. This is
liquid lead. The same stuff they used to dump from the castle walls on to invaders to kill
them. And there’s no burn like a solder burn.
I can attest to that. Right there. That’s 15 years old and it really hurts. When solder
drops on your skin it really sticks there and does not like to come off.
Because of the high temperature, everyone around should be wearing goggles to keep hot
solder and hot iron tips anything like that from damaging eyes.
You want to work on a fire retardant surface like this piece of metal I’ve got.
I’ve got a stone floor around. Make sure there’s nothing around like old
rags, flammable liquids or similar to catch fire.
Also never solder on batteries, directly on to batteries or other live circuits like house
circuits. Make sure that work is not active, charged
or live. The best you can do is damage the circuit; the worst thing you can do is kill
yourself. No batteries. No live circuits. Again, these are the basics of soldering safety.
If you are going to do soldering, I suggest you get training and implement techniques
that are appropriate to you and your type of soldering.