Soldering Techniques

If I can teach my wife to solder, I can teach anyone to solder.  Don't worry, soldering is easy with the right know-how and a little practice.  If you are under 18 years of age, you should have an adult help you with this.

Safety

I don't want to insult anyone's intelligence here, but lets start with which end of the soldering iron to hold.  Don't laugh, I endured a few days of intense pain after picking up the soldering iron by the wrong end.  And yes, I had already been soldering for years.  Interestingly, there was no pain when I picked up the iron but there was a tingling sensation similar to a mild electric shock.  The pain came about an hour later, and I wouldn't wish it on anyone.

When picking up a soldering iron, make sure you are picking it up by the PLASTIC end.  The easiest way to accomplish this seemingly simple feat is to place the iron in a proper stand where the hot end of the iron is safely covered.  This will also protect your tabletop from burns (guilty), keep mysterious holes from appearing in your carpet (guilty), and maintain the pristine condition of your other tools (oops).  All of these problems disappeared for me after I purchased a $10 soldering iron holder.

Preparing the iron

A brand new iron needs to be prepared for use the first time you use it.  To do this, we perform a process called "tinning" the iron.  Tin the iron by wrapping a length of 60/40 solder around the tip.  Turn on the soldering iron, and allow it to heat the solder to the melting point.  Ensure that the molten solder flows around the entire tip of the iron.  Add solder as required.  When done, shake off any excess solder, leaving a smooth shiny tip.  The iron is now ready for use.

Cleaning the iron

As you use the iron, rosin will build up around the tip or there may be an unwanted buildup of solder.  You will need to clean this periodically.  To do this use a wet sponge designed for cleaning the iron.  Quickly wipe the iron across the sponge so as not to burn the sponge or cool the iron excessively.

NEVER!!!!!  Never clean the iron with sandpaper or any abrasive material.  This will prematurely damage the tip.

Note: Water-Free tip cleaners are now available and offer significant advantages over wet sponges.  See sidebar for info.

Soldering

Now the real stuff.  Soldering components and wires to circuit boards, terminals or other components requires care, quickness, and proper technique.  None of this is difficult to master, even if you may be a little shaky.

The proper technique is to heat the component lead on one side, and apply the solder to the other side of the component lead.  Allow the solder to flow from one side of the lead towards the soldering iron on the other side.

Sometimes when you follow the above technique, the solder does not melt.  This is caused by poor heat transfer between the iron and the component lead.  To improve heat transfer, first make sure the tip is clean and clean if necessary.  Then "wet" the tip of the iron with solder, and try to solder the component again.

Quickness is important when soldering.  Too much heat applied for too long can damage the component being soldered, or can cause the trace to detach from the circuit board.  The general rule to follow is to apply the heat for no more than 3 seconds.  There are of course exceptions to this rule such as when soldering large component leads.  Larger leads will require more time.  Smaller leads will require less time.

When soldering, take care not to allow excess solder to form a "bridge" to an adjacent component lead.  This can cause your circuit to fail, sometimes with spectacular fireworks.

Soldering Tools

Soldering Iron Holder


Water-Free Soldering Iron Tip Cleaner

Soldering Iron