Notes on the successful solder joint.

This tutorial, if that's what you want to call it, isn't presented as the definitive method for melting tin & lead around electrical connectors.  On the other hand, it should be enough to get the average person mostly up to speed and on the road toward doing it right.  This is point to point wiring and not about soldering resistors and transistors and other components to a circuit board.

Soldering isn't some sort of alchemy.  It's actually a very simple thing that involves some pieces of compatible metal, a flux agent, the solder itself, and heat.  In an electrical connection, two conductors are placed together in some sort of mechanical connection, heated to an appropriate temperature (180 - 190 C), then solder is applied to and melted around them to hold the connection in place.  Once it cools sufficiently, it's done.

Before you dive headlong into this:


Finally, if you are working on or around a finished item, such as an electric guitar or bass, protect it from burns.  You may heal, but the instrument will need a refin to fix.


The tutorial that follows involves the use of hand tools and a soldering iron.  Be sure to read and follow all the instructions that come with your tools, particularly safety instructions.  Be sure to wear proper eye protection and work in a well ventilated area.

The author of this webpage assumes that you, the reader, have the ability to read and follow directions.  The author also assumes that you, the reader, possess enough common sense to keep yourself out of trouble, or failing that, has the common sense to get help when it is warranted.

The author of this webpage assumes that you, the reader, knows how to properly and safely use these hand tools and the soldering iron.  The author of this webpage will not be held liable for any injury or damage of any kind to any person, animal, or object as a result of the information provided on this webpage.  You, the reader, take sole and complete responsibility for use of the information presented on this webpage.  You, the reader, take sole and complete responsibility if you damage something, burn or otherwise injure yourself, burn or otherwise injure an animal, burn your home or location down, or reduce the value of your most prized guitar or bass as a result of the information provided on this webpage.

You are on your own.  If anything bad happens, handle it.  I don't even want to hear about it.

So, how do you solder a couple wires together?  Simple.  Hook them together, heat them with a soldering iron, flow solder around them, allow them to cool.  Lesson complete.  Really.  That's all there is to it.  If you can nail this down and not burn down the house or brand your fingers, you're on the right path.

Here are a few examples and images to help illustrate some basic methods and tips to help solder a good joint.  Please click the images for a wider view, which will open in a new window or tab.  For reference, the wire used in the images is 18 gauge.  It's really a bit big for guitar/bass, but it's more macro photography friendly.

Implements of Destruction Implements of Destruction.  These are the tools that I typically use when diving into a soldering project.  They are, left to right: small wire cutters, small long-nose pliers, wire strippers, pick tool, solder, and an iron.  It's important to size tools to the job, so I use small tools because the jobs I do involve physically small parts.  Cutters should be sharp and in good condition.  I use "automatic" strippers, but any type that is appropriate for your wire size is good.  The pick tool is optional, but I find it useful for any number of little things.  Solder sizes shown are .064" and .032", and I'll use what is appropriate for the task at hand.  My soldering iron is a Weller soldering station, but a simple single temp pencil style iron is perfectly fine (and inexpensive).

That little yellow thing under my iron is a cellulous sponge.  The sponge is kept damp and I wipe the soldering iron tip on it as needed to keep the tip clean.  Once clean, the tip gets tinned in the same manner as wire (see below).  Keep the soldering iron tip clean so that it conducts heat properly.

First off, let's cover stripping wire so it's easier to work with.

We are nearly always working with stranded wire and if we just yank off the insulation jacket, we get this nifty little bundle of strands that poke straight out of the jacket.  Try bending them in some sort of meaningful manner and they take off in less than meaningful directions.

With your strippers, pull the jacket about 1/8" off the wire so you get a gap like that shown.  

Now grasp the cut end of the jacket and simultaneously pull and twist the jacket off the wire.
It takes a bit of practice and it's easier with some wire than others, but once you get it you end up with a nice twisted wire end.
There is essentally no twist here,and it will be miserable to work with, even if tinned, because the strands will separate when bent.
If you recall, I used the word "tinned" above as a descriptor of compatible metals.  In the context of soldering, tinning is a process where a wire or connector is coated with solder.  This is done for a couple reasons: (1) Parts will join more readily when tinned, and (2) It helps keep stranded wire in a bundle.

Strip the wire as shown above then heat it with your iron.  Once hot, flow a small amount of solder onto and into the strands.  Allow to cool and there you have it.

Once the wire is tinned, you can easily prep it for connection to other wires or devices such as potentiometers (pots).  Because the strands are tinned, they'll generally stay in a neat bundle when bent.
For example, I've hooked the tinned & prepped lead from above above to one solder lug of a pot.  Note that I closed the hook for a good mechanical connection.  I then touched and held the tip of my iron to BOTH the solder lug and the wire to heat them.  Then I flowed just enough solder onto and into the joint to secure it.  Once cooled, you have the next image.

How long you heat the joint is highly variable.  Working on cold nights in the garage will make it take longer.  An iron with too little power (or not turned up enough) will take longer.  Heavier materials take longer to heat too.  However, it only takes 3-5 seconds or so for what we're doing here.  If you're melting insulation, you may be on it too long.  Practice will help you with this.

Creating a small loop as I did above makes it easier to tell when you've flowed enough solder because the loop is filled with solder.  You really do not want to flow too much solder into the joint.  MORE IS NOT NECESSARILY BETTER HERE!  

Another point to remember - and this one is very important: Do not move the joint until the solder has solidified.  To do so will create what is referred to as a cold solder joint.  With small wire and lug sizes, you only have to wait a few seconds for the solder to cool enough.  It'll still be hot enough to burn your fingers, so do be careful.

When looking at new solder joints, good joints are usually shiny and cold joints are usually dull.  I say usually as a disclaimer because it isn't like this all the time (though mostly).  As per Bob of Looperlative Audio Products (Thanks!), lead free solder will nearly always produce a dull looking joint.  Just let it sit long enough, okay?

Occasionally there is a need to connect two adjacent solder lugs or other connections.  To do this, strip a sufficient amount of jacket from your wire as shown above, then tin it.  More wire than you need is perfectly okay because you can, and should, cut off any excess.

Use your long nose pliers to route the tinned lead through the lugs as required and bend the end to hold the whole thing in place.

Now heat and apply solder to each lug and connected wire.  Don't try to heat the lead between lugs; do them individually in the same manner as you'd solder a single lug.  Allow to cool then clip off any excess lead legth.

To speed the cooling process, allow the solder to solidify, then grasp the joint firmly with your long nose pliers.  This will "sink off" the heat from the connection to the relatively heavy steel (and greater mass) of the pliers.

This should be enough to get you on the road toward doing small and light solder jobs such as you'd find in an electric guitar or bass.  This isn't a task that most people can just pick up and be good at from the get-go.  Practice is a good thing, kind of like playing your instrument, so get a few supplies and start soldering.  Start with some 20 gauge copper wire and a few solder-style terminal strips, which will let you do everything that I've shown you here.  You will quickly learn that you don't have enough hands to hold the parts, iron, and solder at the same time.  This is when you'll start getting crafty with clamps, clips, pieces of wood, etc, that you have floating around.  For example, a 1/4" hole drilled in a piece of wood that is then clamped to a bench REALLY helps when making cables.

Be safe, and have fun!

Copyright 2009 Ken Baker and