SOLDERING – how to do it right?

In case you are an engineer or someone who is interested in building your own cool products or fixing something around the house, soldering will be a good skill to learn.

What is Soldering?

Soldering is the joining of metals by a fusion of alloys which have relatively low melting points. In other words, you use a metal that has a low melting point to adhere the surfaces to be soldered together. Consider that soldering is more like gluing with molten metal, unlike welding where the base metals are actually melted and combined. Soldering is also a must have skill for all sorts of electrical and electronics work. It is also a skill that must be taught correctly and developed with practice.

Tools required for soldering?

Some tools which you should keep by your side before soldering are soldering gun, soldering gun stand, wire cutter and stripper, soldering wik, solder.

What is solder made of?

The choice of solder is also important. There several kinds of solder available but only a few are suitable for electronics work. Most importantly, you will only use rosin core solder. Acid core solder is common in hardware stores and home improvement stores, but meant for soldering copper plumbing pipes and not electronic circuits.

For most printed circuit board work, a solder with a diameter of 0.75mm to 1.0mm is desirable.

How to choose soldering gun?

Here we give you a few tips on how to solder the component’s of an electronic circuit properly. For normal electronics use, a soldering iron is generally the tool of choice as its small tip and low heat capacity is suited for printed circuit board work (such as assembling kits). A soldering gun is generally used in heavy duty soldering such as joining heavy gauge wires, soldering brackets to a chassis or stained glass work.


  1. A PCB typically has two sides. Place the component with its leads through the appropriate holes, with the body of the component on the side without metal printing, and the long ends of the leads on the same side as the metal printing.  If the component does not stay on its own, bend the leads slightly against the sides of the holes they are in.
  2. You can start by warming up the soldering iron thoroughly. This is especially important if the iron is new because it may have been packed with some kind of coating to prevent corrosion.
  3. While the soldering iron is warming up, prepare a little space to work. Moisten a little sponge and place it in the base of your soldering iron stand or in a dish close by. Lay down a piece of cardboard in case you drip solder and make sure you have room to work comfortably.
  4. To test if the soldering iron is hot, touch the solder slightly to the soldering gun, some fumes will come out if the iron is hot.
  5. Once the soldering gun is heated up thoroughly coat the soldering tip in solder. Make sure that the tip is totally coated in solder. Wipe the tip off on the wet sponge to remove the excess flux residue. Do this immediately so there is no time for the flux to dry out and solidify.
  6. Heat the lead and the board, otherwise the solder will simply pool and refuse to stick to the unheated item. For this place the tip of the soldering iron so that it touches both the component’s lead, and the metal printing on the circuit board.  Touch the tip of the strand of solder to the component lead and solder pad, but not the tip of the iron. *Warning* Leaving the soldering iron on a circuit board too long can damage it.

How to de-solder?

Desoldering is the removal of solder and components from a circuit for troubleshooting, for repair purposes, component replacement, and to salvage components. Specialized tools, materials, and techniques have been devised to avoid damaging the circuit board, surrounding components and the component being removed in the desoldering process. There are two ways to remove the solder. They are:

With a desoldering pump (solder sucker): Set the desoldering pump in position by locking the plunger down. Then touch the joint to be desoldered, using both pump and the heated soldering gun. After the solder is melted, plunger is released to suck away the molten solder into the pump. Repeat this process to remove the solder completely or maximum solder removed.

Using a desoldering wire/copper braid:Put the desoldering wire and the heated soldering gun near the joint. As the solder melts, it gets sticked to the desoldering wire. After this, remove the desoldering wire first followed by the soldering gun.

After the solder is taken out, you will be able to take out the component lead easily. If you are not able to take out the component, then apply the heated solder iron and simultaneously try to pick the component by taking care to avoid burning yourself.


Remember that when soldering, the flux in the solder will release fumes as it is heated. These fumes are harmful to your eyes and lungs. Therefore, always work in a well-ventilated area and avoid breathing the smoke created. Hot solder is also dangerous. It is surprisingly easy to splash hot solder onto yourself, which is a thoroughly unpleasant experience. Eye protection is also advised.

Check the soldering video in link provided to learn more about tools used for soldering

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2 responses to SOLDERING – how to do it right?

  1. Your post was very informative thank you for that

  2. Erasmo Penz

    Most important thing to be kept in mind when working with soldering iron is not to touch the tip of the iron as it is extremely hot. Soldering material used for the purpose is an alloy of tin and lead and is called flux. Before you put solder over the required area, heat up the surface to be soldered by touching the tip of the hot iron. Application of the solder is called “tinning”since percentage of tin is more in the flux. However, flux can be of various types depending upon the things to be soldered. ^

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