How to Solder

by Santosh Das | Last Updated On July 5, 2019

How to Solder – Learn how to solder like a Professional.

How to Solder with Flux and Solder Wire – Learn how to solder circuit boards and wires to metal.

What is Hand Soldering?

Soldering electronic components by hand is a very important part of mobile phone repairing or repairing and rework of any PCB (Printed Circuit Board). Good soldering can increase the life and performance of any PCB. Poor soldering can lead to failure of the PCB. This basic hand soldering guide is a tutorial on how to do hand soldering like a professional.

Tools and Consumables Needed for Hand Soldering

You will need following tools and equipment:

1. Soldering Iron – Always try to buy a good ESD-Safe soldering iron. A 50 watt soldering iron is good for soldering any electronic component to a PCB.
2. Soldering Station – If you are a professional, try to get a good quality branded ESD-Safe soldering station. It will have a separate unit (Station) to control temperature and a soldering iron plugged into the station. Goot Soldering Station is One of the Best.
3. Flux Cored Solder Wire: It is always better to use flux cored solder wire. Flux will help to remove any oxide and contamination from the surface of the PCB and leads of the electronic components. This will help better soldering. Cookson Solder Wire is One of the Best.
4. No Clean Liquid Solder Flux: This will help to remove any oxide from the surface of the Board and the Leads of electronic components.
5. Other consumables that may be needed are Desoldering wick, desoldering pump, PCB holder, conductive pen, flux pen, cleaning sponge etc.

Video : Best Mini Soldering Station

Safety and Precaution

While soldering, there are some safety measures to follow to avoid any damage and injury:

• Never touch the tip or bit of the hot soldering iron. Temperature of the tip can be as high as 500 degree Celsius that can lead to serious burn and injury.
• When not using the soldering iron, always keep it on the iron stand or iron holder.
• Avoid breathing in the fume or smoke during soldering. Use a smoke absorber while soldering.
• When soldering is done, always wash your hand properly.

Preparation of Soldering Iron

1. Always keep a piece of wet solder cleaning sponge on the iron stand.
2. Place the soldering iron on its holder or stand and switch ON the plug in the power cord.
3. Switch ON the power of the Iron or the Soldering Station.
4. Wait for few seconds while the desired temperature is reached.
5. Put some solder wire at the tip of the iron. If the wire melts immediately then it means that the iron is ready for soldering.
6. Clean the tips of the soldering iron with wet cleaning sponge before and after soldering.
7. When soldering is done, clean the tip using the cleaning sponge and leave some solder on the tip. This will prevent the tip from oxidation and increase its life.

Video : How to Solder and Clean $ Tin Soldering Iron Tip

How to Solder – Step by Step Tutorial

1. Hold the soldering iron like a pen near the handle base. Make sure not to touch the tip or the metal part as they are too hot.
2. Place the electronic component at the desired place. Apply some solder flux.
3. Bring down solder wire and soldering iron tip together to the point where the component lead and the Copper Track of the PCB meets. Melt enough solder at the junction. Make sure there is no bridging.
4. Soldering should be shiny and well shaped. If you are using lead-free solder then the soldering may not look shiny even if the soldering has been done properly.
5. Do not touch the PCB track with hot iron for too long. Remove the iron as soon as the solder melts.

I hope now you know the proper way of how to solder by hand like a professional. Do share your thoughts and ideas via comments.

When to use it and how to do it

Figure 1. Brazing takes place above 840 degrees F but below the melting point of the base metal.Source: CDA, Copper Tube Handbook.

Four processes to consider when joining copper and copper alloys are mechanical couplings, welding, soldering, and brazing. Brazing is suitable for small parts and when high joint strength is required. According to the American Welding Society (AWS), the strength of a brazed joint can meet or exceed that of the metals being joined. It is important to know when to choose brazing and how to perform the process.

From a process standpoint, soldering and brazing are essentially the same. The only differences are the filler metals used and the amount of time and heat required to complete the joint. AWS defines soldering as a joining process that takes place below 840 degrees F, while brazing takes place above 840 degrees F but below the melting point of the base metal. In actual practice for copper systems, most soldering is done at temperatures from about 450 degrees F to 600 degrees F, while most brazing is done at temperatures from 1,100 degrees F to 1,500 degrees F. When brazing copper tube, however, the annealing of the tube and fitting that results from the higher heat can cause the rated pressure of the system to be less than that of a soldered joint.

Copper’s melting point is 1,981 degrees F (liquidus) and 1,949 degrees F (solidus). For brazing, it is important to know the melting points of the metals to be joined and the filler metal. The difference between the solidus and liquidus state is the melting range, which may be important when selecting a filler metal. It indicates the width of the working range for the filler metal and the speed with which the filler metal solidifies after brazing. Filler metals with narrow ranges, with or without silver, solidify more quickly and, therefore, require careful application of heat. The liquidus temperature is the minimum at which brazing will take place. See Figure 1 for the melting ranges of some common brazing metals.

To Braze or Not to Braze

According to Lucas-Milhaupt’s What Brazing Is All About (), the choice to braze comes down to five factors:

1. The size of the parts to be joined. Brazing is more often used for small parts and requires heating a broad surface to bring the filler material to its flow point, which is often impractical with large pieces.
2. Thickness of the metal sections. The broader heat and lower temperature used in brazing, as opposed to welding, permit the joining of sections without warpage or metal distortion. The intense heat of welding may burn through or warp a thin section.
3. Joint configuration. Brazing needs no manual tracing, and the filler metal is drawn through the joint area by capillary action, which works with equal ease on straight, irregular, or tubular joints.
4. Nature of the base metals. For joining dissimilar metals, brazing won’t melt one or both of the metals if the filler metal is metallurgically compatible with both base metals and has a melting point lower than either of the metals to be joined. Note that copper alloys can be readily brazed to other metals, such as cast iron, tool and stainless steels, nickel alloys, and titanium alloys.
5. Number of joints to be made. If you are making many joints, manual brazing is quick and simple, and automated brazing may be accomplished inexpensively using simple production techniques.

Brazing Fluxes

Brazing fluxes for copper are water-based, dissolve and remove residual oxides from the metal surface, protect the metal from oxidation during heating, and promote wetting of the surfaces to be joined. Brazing fluxes also provide you with an indication of temperature (see Figure 2).

The most commonly used fluxes and brazing filler materials for copper and copper alloys are shown in Figure 3, and a guide to their use is shown in Figure 4. This and other detailed information can be found in The Welding Handbook, 8th Edition, Vol. 8, published by the American Welding Society and available from the Copper Development Association under the title Welding Copper and Copper Alloys, A1050-72/97.

The Process

The same basic steps are used for brazing as for soldering, with the only differences being the use of fluxes, filler metals, and the amount of heat used.

In general, both lap and butt joints can be made. Be sure to remove all oxides and surface oils with abrasive cloth, pads, or brushes before joining the metals. Such contaminants interfere with the proper flow of filler metal and may lessen the joint strength or cause failure. Chemicals cleaners may be used if they are thoroughly rinsed off, but be sure you don’t touch the clean surface with bare hands or oily gloves.

Apply a thin, even coating of flux with a brush to both surfaces soon after cleaning. Do not apply the flux with your fingers because the chemicals in the flux can be harmful if it comes in contact with your eyes, mouth, or open cuts. Copper-phosphorus and copper-silver-phosphorus metals (BCuP) are considered self-fluxing on copper-base metals.

Support the surfaces securely and ensure an adequate capillary space between them for the flow of the molten brazing filler. Excessive joint clearance can lead to cracking under stress or vibration. A joint clearance of 0.001 to 0.005 in. will develop the maximum joint strength and soundness.

Figure 2. The table shows how fluxes respond at various temperatures and at what maximum temperature the flux will protect the metal.Source: CDA, Copper Tube Handbook.

Use only the amount of heat necessary to melt and flow the filler metal. Overheating the joint or directing the flame into the capillary space can burn the flux, destroying its effectiveness and preventing the filler metal from entering the joint properly. Apply the heat around the joint area to draw the filler metal into the capillary space. When dealing with an open flame, high temperatures, and flammable gases, safety precautions as described in ANSI/AWS Z49.1, “Safety in Welding, Cutting and Allied Processes,” must be observed.

Allow the completed joint to cool naturally. Shock cooling with water may stress or crack it. When it is cool, clean off any remaining flux residue with a wet rag and test all completed assemblies for joint integrity.

Everyone can learn how to solder. And it’s an important skill to know want to build electronics.

Basic soldering is easy. All you need is a soldering iron and some solder. When my dad taught me as a teenager, I remember picking it up quite fast.

In this soldering guide, you’ll learn first learn to solder two wires. Then you’ll learn to solder components on a circuit board. If you’re already familiar with this, consider jumping over to my guide on SMD soldering or reflow soldering.

Also, check out my article on the soldering tools you need to get started.

Preparing Your Workbench

Prepare your workspace. Find your soldering iron and your solder wire and start heating the iron. A pair of wire cutters usually comes in handy too.

Place your soldering iron in a holder. If you don’t have a holder, at least make sure the tip is not touching anything while you heat it.

If you have a temperature-controlled soldering iron, check out my guide to choosing the right soldering temperature.

Clean the Tip

When the iron is hot, the first thing you should do is to clean the tip to remove old solder from it. You can use a wet sponge, a copper scouring pad, or something similar.

Tin the Tip

Before you start soldering, you should tin the tip of the soldering iron. Which just means to melt some new solder onto the tip. This makes the tip transfer heat faster and thereby making the soldering easier and faster.

If you end up with big droplets of tin on your tip, just clean it again as shown above.

TIPS: If you tin the tip before you put down the soldering iron for the day, it is said that the tip should last longer.

Soldering Two Wires

If you want to join two wires with solder, the first thing you should do is to tin the two wires. Note that the wire will get hot, so you should consider holding it with some tweezers or similar.

Place the tip of the iron on the wire and let it heat for a few seconds. Then add some solder until the wire is soaked with solder.

If it is a thick wire, you should turn up the heat on your iron (if possible) to make the wire heat up faster. Repeat the tinning process on the other wire.

Now place the two tinned wires together and hold still while heating them with the soldering iron so that the tin on both of the wires melt together.

How to Solder a Circuit Board

Next, let’s see how to solder through-hole components to a circuit board.

Start by placing the component into its holes. Place it so that its legs come out on the same side as the solder pads.

On the solder side of the board, bend the legs of the component a bit. This way it won’t fall out when you flip the board upside down.

Feel free to add several components at once.

Now you’re ready to start soldering.

Put the tip of the iron on the pad so that it heats both the leg of the component and the pad of the circuit board.

Heat them for a second or so before you apply solder. Keep the iron on the joint while you add solder.

When you have enough solder, remove the solder wire. Then remove the soldering iron tip from the joint.

Inspect your solder joint to see if it looks okay. A good solder joint has kind of a cone shape.

If you are happy with your soldering, cut off the component lead from above the solder joint.

But don’t cut it too short! That will make your life hard if you for some reason have to desolder the component later.

Watch out for Cold Solder Joints!

Always make sure that you apply enough heat! Both to the pad and to the pin. Otherwise, you might end up with a cold solder joint.

A cold solder joint often looks okay at first glance. But when you look more closely, you’ll see that there’s a tiny gap between the solder and the pin. This means that the pin isn’t properly connected to the pad.

This can lead to some serious frustration when your circuit doesn’t work and you are trying to figure out why.

How to Get Good at Soldering

Do you want to learn to solder? The quickest way to get good at soldering is to practice on a lot of circuits. For example, get yourself some soldering kits to practice on.

Or you can find yourself some interesting circuits on your own and solder them onto a stripboard.

Let me know what questions you have around soldering in the comment section below!

Learning how to solder wires is more important than ever. Homeowners are increasingly taking on repairs of home appliances such as dishwashers and refrigerators. When you know how to solder, small appliances like electric teapots and simple electronic items no longer need to be discarded when they malfunction. With patience and a little practice, you can learn how to solder wires for repairs, as well as for fun projects.

In this simple project, you will solder together the exposed ends of two plastic-coated stranded copper wires. No special skills are needed to perform this task. Because the materials are so inexpensive, you will have ample opportunities to practice on scrap wires before making your final solder joint.

Project Metrics

• Working Time: 5 minutes
• Total Time: 20 minutes
• Skill Level: Beginner
• Materials Cost: $25 to $50

Tools and Supplies You Will Need

• Soldering iron
• Soldering iron tips
• Sponge and water
• Soldering iron stand
• 60/40 rosin core solder
• Rosin paste flux
• Heat shrink tubing
• Heat gun
• Wire stripper
• Eye protection

Instructions

In lieu of purchasing separate soldering components, you may wish to buy a soldering iron station that includes a soldering iron, stand, and a tip cleaner. Since the entire station plugs into an outlet, strain is reduced on the soldering iron cord since the cord does not have to run directly into the outlet. This is important for the delicate hand movements you make when soldering.

Leaded 60/40 solder, composed of 60-percent tin and 40-percent lead, has long been used for soldering and is safe if properly handled. For the utmost in safety, choose lead-free solder, composed of 99.3-percent tin and 0.7-percent copper.

Prepare a Safe Working Space

Make sure that your work area is well-ventilated, especially when working with lead-based solder. Because the tips of soldering irons can range between 600 and 800 degrees Fahrenheit, work on a non-flammable surface since molten solder can drip. If working with lead-based solder, be sure to thoroughly wash your hands after working with the solder. Use eye protection whenever working with solder.

Strip the Wires

Strip away 1/2-inch of the plastic coating from the wires with the wire stripper. Try not to leave too much or too little of the plastic coating. Stripping away too little plastic coating will hinder soldering. Stripping away too much plastic coating will expose an excessive amount of copper wire and require you to use more heat shrink tubing. Be sure to use the correct gauge on the wire stripper so that you do not accidentally cut away strands of wire.

Add the Heat Shrink Tubing

Find the smallest diameter tubing that will fit over the plastic-coated wire. If you choose tubing that is too large, it will not shrink down to the correct size. In terms of length, the tubing should cover the splice, plus another 1/2-inch on each end. Slip the heat shrink tubing onto the wire and put it down the wire about a foot for now.

Join the Wires

Gently flay the individual strands of wire. Push the wires toward each other, interlocking the strands. Loosely twist the meshed wires. If you twist the wires too tightly, the solder will not be able to penetrate. Yet the joint should still remain smaller in diameter than the heat shrink tubing.

Position the Wires

Position the wires so that they are elevated over the work surface. Wires that lay flat may get stuck to the surface by the solder. Alligator clips or even household metal spring clamps can be fashioned to elevate the wires.

Add the Rosin Flux

Carefully rub a small amount of the rosin flux paste to the joined wires so that all of the copper is covered. The rosin flux will help draw the solder into the meshed strands.

Prepare for Soldering

Plug in and turn on the soldering iron. Unroll about six inches of solder so that the end is exposed and ready to use.

As the soldering iron heats, rub the tip across a wet sponge to remove any previous oxidation. For a new soldering iron heating up for the first time, this is not necessary.

Solder the Wires

Touch the heated tip of the soldering gun to the wire joint. Hold the tip firmly in place for a few seconds to heat up the wire. Touch the exposed end of solder lightly to the wire joint. The heat should cause the solder to instantly melt and draw into the meshed strands.

Shrink the Tubing

After the solder has fully cooled, slip the heat shrink tubing over the joint. Make sure that it is evenly positioned. Run the heat gun over the tubing until it constricts completely.

Overview: What is soldering and when should you use it?

• Soldering is a process in which two or more metal items are joined together by melting and then flowing a filler metal into the joint—the filler metal having a relatively low melting point.
• Soldering is used to form a permanent connection between electronic components.
• The metal to be soldered is heated with a soldering iron and then solder is melted into the connection.
  • Only the solder melts, not the parts that are being soldered.
  • Solder is a metallic “glue” that holds the parts together and forms a connection that allows electrical current to flow.
• You can use a solderless breadboard to make test circuits, but if you want your circuit to last for more than a few days, you will want to solder the components together.

Materials and Equipment

• A soldering iron
  • A soldering iron is used to heat the connections to be soldered.
  • For electronic circuits, you should use a 25- to 40-watt (W) soldering iron.
  • Higher wattage soldering irons are not necessarily hotter; they are just able to heat larger components. A 40-W soldering iron makes joints faster than a 25-W soldering iron does.
  • A soldering iron can be purchased at hardware stores and at most large department stores.
• Rosin core solder
  • Solder has a lower melting point than the metals that are being connected do. The solder melts when it is heated by the soldering iron, but the metals being joined will not melt.
  • The rosin core acts as a flux. It prevents oxidation of the metals that are being connected, and enhances the ability of the solder to “wet” the surfaces that are being joined.
  • Solder that is used to join copper pipes has an acid core, which is appropriate for pipes, but will corrode electronic connections. Use solder that has a rosin core.
  • For most electronics work, a solder with a diameter of 0.75 millimeters (mm) to 1.0 mm is best. Thicker solder might make soldering small joints difficult and also increases the chances of creating solder bridges between copper pads that are not meant to be connected.
  • An alloy of 60/40 (60% tin, 40% lead) is used for most electronics work, but lead-free solders are available as well.
• Stand on which to hold the hot soldering iron
  • There are a variety of stands available. It is important to always keep the hot iron in its stand when not in use.
• Sponge
  • The damp sponge is used to clean the tip of the iron.

• Solder braid
  • This is used to remove solder.
  • To use the braid, place it over the solder to be removed and heat it from above with the iron. The solder will flow into the braid.
  • Solder braid is used to extract an electronic component that is soldered onto a board.
  • It is also used to reduce the amount of solder on a connection.
• Prototype board
  • A prototype board is used to assemble the circuit. The board shown is from but Jameco Electronics also supplies prototype boards.
  • Prototype boards have copper tracks or pads for connecting components.
• Steel wool or fine sandpaper
  • This is used to clean connections prior to soldering.
  • Solder will not flow over a dirty connection.
• Crocodile clips
  • These can be used as heat sinks, if needed.

Safety Precautions

1. Caution: A soldering iron can heat to around 400°C, which can burn you or start a fire, so use it carefully.
2. Unplug the iron when it is not in use.
3. Keep the power cord away from spots where it can be tripped over.
4. Take great care to avoid touching the tip of the soldering iron on a power line. If a power cord is touched by a hot iron, there is a serious risk of burns and electric shock.
5. Always return the soldering iron to its stand when it is not in use.
6. Never put the soldering iron down on your work bench, even for a moment!
7. Work in a well-ventilated area.
8. The smoke that will form as you melt solder is mostly from the flux and can be quite irritating. Avoid breathing it by keeping your head to the side of, not above, your work.
9. Solder contains lead, which is a poisonous metal. Wash your hands after using solder.

Reliable operation of a circuit with soldered connections depends on good soldering practices. Here are some tips for successful soldering.

1. Plan before you start to solder. Identify all the parts that you will be using.
2. It is helpful to attach each part to a piece of paper and write what it is and its value (for example, resistor #1: 100 ohms).
3. Some components, such as LED’s, must be placed the correct way around in order to function.
4. The following is a suggested order for the installation of various components:
   • Integrated circuit (IC) holders (note the orientation). The IC will be added later.
   • Resistors
   • Capacitors, less than 1 micro farad
   • Large capacitors, 1 micro farad or greater, note the orientation.
   • Diodes, note the orientation.
   • LED’s, note the orientation.
   • Transistors, note the orientation.
   • Solid wire connections between components on the board
     • Solid wire is fairly rigid, so it will stay in place once attached.
   • Stranded wire to parts that are connected by wire to the circuit
     • Stranded wire is more flexible than solid wire.
   • Integrated circuits
     • Connect them the correct way around.
     • Many IC’s are static sensitive.
     • Leave IC’s in their antistatic packaging until you need them, then ground your hands by touching a metal water pipe or window frame before touching the IC’s.
     • Carefully insert IC’s in their holders. Make sure all the pins are lined up with the socket, then push down firmly with your thumb.

Eugene is a qualified control/instrumentation engineer Bsc (Eng) and has worked as a developer of electronics & software for SCADA systems.

What Is Soldering?

Soft soldering is a technique used to bond metal components together. The components could be electrical wires, terminals or electronic components. Printed circuit boards (PCBs) used in electronic devices are populated with lots of electronic components and these components must be attached securely. Solder is like glue that fixes the components to the PCB. Unlike glue, however, which physically bonds materials together, solder also ensures that there’s a good electrical connection between component and PCB.

Soldering is also used in plumbing to join capillary fittings to pipes, in metalwork and in jewelry making. The term soft soldering originates from the fact that soft metal alloys are used and lower temperatures are required to melt them. Hard soldering or brazing is another soldering technique that uses harder metals such as silver and brass for joining metal items, again typically jewelry and bicycle frames.

Top and underside of a PCB showing the solder joints. Pins of the integrated circuits (ICs) and other components pass through holes in the PCB and are bonded electrically to copper tracks using blobs of solder.

Axonite and Magnascan via Pixabay

What Is Solder?

Solder is a fusible metal alloy used for making solder joints. It comes in rolls of varying gage wire, as a paste and in bars. Originally solder was an alloy of tin and lead; however, lead is toxic and in the EU, the WEEE and RoHS directive came into effect in 2009 restricting the use of lead in consumer products. Lead-free solder now contains tin, copper, silver and other alloys.

Solder has a melting point of typically between 50° C to over 200° C (122° F and 392° F). Solder wire used for electrical/electronic joints is normally flux-cored. Flux, made from a resin that melts when heated, flows over the joint when soldering. It aids flow of solder and also shields the solder and components from oxygen in the air. This prevents an oxidation film from forming which would make it more difficult for solder to stick and also potentially cause a “dry joint” or bad electrical connection.

A roll of solder wire.

Typical electric soldering iron on a stand. The blue sponge is used for removing flux residue from the tip of the iron.

Soldering iron bit.

What Tools are Needed for Soldering?

Solder joints are made with a tool called a soldering iron. This is powered by electricity or gas, but older irons used for metal work were heated with a blow torch. It consists of a handle with a copper bit at the end, usually coated with a metal such as nickel or iron to minimise oxidation of the bit and improve thermal conductivity when soldering. An electric element or catalytic converter heated by burning gas heats the bit to about 180° C or higher.

Other tools used for soldering are:

• Side cutters (wire snips) for cutting wire and leads of components
• Desoldering pump (“solder sucker”). This sucks up molten solder from a joint, allowing the removal of wires or components.
• Tip cleaner. During normal use, a moistened sponge is used. However abrasive tip cleaners which use curled wire are capable of removing harder deposits on the iron’s tip.
• Soldering iron stand for holding the hot iron in between uses. Irons aren’t always supplied with stands, but they can be bought separately

• Vice. A small vice is useful for holding connectors or circuit boards while soldering. Usually these vices have rubber coverings for their jaws to avoid crushing components and sometimes a suction base for sticking to a bench. Some vices clamp onto the edge of a worksurface
• Solder wick. This is braided copper wire, used to “soak” up solder when de-soldering.
• Flux is used when soldering with non-flux cored wire. This is mostly used when soldering plumbing fittings or metalwork joints. Flux is available as a paste or liquid.

De-soldering pump or “solder sucker” for sucking up molten solder when de-soldering components.

Skill Level

Start to Finish

Tools

• brush
• propane torch
• wet cloth
• safety glasses

Materials

• soldering wire
• copper pipes and fittings
• flux

Like this? Here’s more:

• Pinterest
• Facebook
• Twitter

Step 1

clean and apply flux to pipe

Clean and Apply Flux

Copper pipe needs to be cleaned before it can be soldered. First, use sandpaper to clean the inside and outside of the pipes and fittings that will be joined.

Next, use flux to remove impurities from the inner and outer surfaces of both pipes. Spread the flux over the entire surface with a brush. Then, slide the two pieces together.

Step 2

solder the joint

Solder the Joint

While wearing safety glasses, fire up the propane torch. All three parts of the flame should be blue; if the flame is orange, turn gas down.

Hold the flame on the tip of pipe to heat. The flux will turn to liquid and the pipe will change color slightly. When the pipe is heated, touch the soldering wire to the joint. If done correctly, the solder will be drawn into the joint.

Once the joint is soldered, use a wet cloth to clean up the area.

Table of Contents:

Before you begin

You will need the following equipment:

1. A temperature-controlled soldering iron of 25W or more
2. A tip cleaner such as a brass sponge or a wet sponge
3. Solder (leaded is easier to work with than lead-free)
4. (Optional) Helping hands
5. Safety glasses

Note: molten solder is extremely hot! Irons heat up to around twice the boiling point of water, so be extremely careful. Wear safety glasses when soldering.

Step 1: Heat your iron to the appropriate temperature

For through-hole components in a circuit board, you will want 600-700 degrees fahrenheit.

If you’re soldering a larger connections, with more copper that’s dissipating heat, then you may want a slightly higher temperature. With a temperature-adjustable iron you can see what works and adjust accordingly.

Step 2: Make your connection mechanically stable

While your iron is heating up, you can work on making your components stay in place without your help. This is where your helping hands may come in handy. Use them to help you arrange your components to be stable without you needing to hold anything. If you’re soldering a through-hole component in a circuit board, you can bend the leads of the component into a V-shape so that it stays in place flush against the board. For components without long leads, you can use a piece of tape to hold them in place.

Step 3: Clean the tip of your iron

You can check whether your iron is close to its final temperature by touching your solder to the end of the iron and seeing if it melts. When you do this, you’ll see some smoke come out. This is not the metal vaporizing, but rather the flux inside of it is burning. Flux is a mild acid that eats away at the oxidation layer that forms on the surface of hot metals. Without flux in the solder to clean your surfaces, you would have a very hard time getting the solder to wet.

Clean your iron using a brass sponge or a wet sponge to remove any oxidation or excess solder from the tip. Remember to always keep your tip clean while you’re soldering. A dirty tip is covered in metal oxides that transfer heat badly and can result in poorly soldered joints.

Step 4: Apply heat and solder

Touch the flat part of your iron’s tip to one side of the joint, while feeding solder from the other side of the joint. The idea is to heat up the entire joint to the melting temperature of solder, so when you touch the solder to the surfaces it melts right on. The only way you can ensure a good electrical connection is by letting the solder flow over the components you’re joining. Don’t apply the solder directly to the tip of the iron. For through-hole components, hold the iron against both the lead and the pad.

Small joints can heat up within a few seconds, but larger joints can take a minute or two. Keep the joint steady for a few seconds after removing the iron, as the solder needs time to cool. Remember that the joint is hot now! don’t touch it with your fingers right away.

Step 5: Inspect the joint

The solder should have wetted to both surfaces. On pads of a printed circuit board, the solder should be covering the entire pad, and it should make a volcano shape between the pad and the lead, indicating good adhesion. Once the joint is perfect, clip the leads of through-hole components.

Common mistakes, or what NOT to do

Now that we’ve gone over what to do, let me tell you what NOT to do.

Don’t put a blob of solder on the iron and then try to transfer it to your joint. This burns away all of the flux in the solder, which prevents the flux from cleaning the metal surfaces. Furthermore, it’s easy to transfer the solder blob away from the iron without actually making it wet to the joint. I guarantee you that this will result in an awful electrical connection, so don’t do it.

Related Articles

• How to Join Two Copper Pipes Without Welding
• How to Cap a T Pipe Going to a Sprinkler Line
• How to Splice Galvanized Pipes
• How to Connect PVC to Brass Plumbing
• Removing Galvanized Steel and Black Iron Fittings

As an alloy of copper and zinc, brass is compatible with copper, and manufacturers produce many common plumbing fittings with the material. Solder adheres as well to brass as it does to copper, so the fittings are usually molded with slip joints so you can solder them to the pipes. It’s easy to solder copper plumbing if you do it right but troublesome if you make a mistake, and a common mistake is to solder pipes while water is dribbling through them. If the pipes and fittings are dry, however, you shouldn’t have any trouble producing a watertight seal.

Prepare the pipe onto which you are going to solder a brass fitting by first turning the water completely off so that none is dripping from the end. If the pipe is installed horizontally and water is pooling inside it, swab it out with a rag.

Deburr the end of the pipe with a file if you used a hacksaw to cut it. Clean off oxidation and dirt with 120-grit sandpaper. Proper preparation of the pipe ensures adhesion of the solder.

Spread soldering flux on the outside of the pipe and the inside of the brass fitting with a small brush. The brush usually comes with the flux. Slip the fitting onto the pipe and rotate it into the correct orientation.

Heat the joint with a propane torch until the flux begins to boil. When it does, it will turn black and begin to smoke. Remove the heat when this happens.

Unroll a coil of lead-free solder and touch the tip to the joint as soon as you remove the heat. Move the solder completely around the pipe as it melts and seeps into the joint. Work quickly. The metal stays hot enough to melt solder only for a few seconds.

Solder the other joint of the fitting as soon as the solder in the first joint turns dull and solidifies. Let the fitting cool for 10 to 20 minutes before you touch it.

Related Articles

• How to Install a Frost Proof Faucet
• How to Solder Plumbing Valves
• How to Remove Rusted Galvanized Pipe From a Wall
• How to Remove an Old Corroded Galvanized Drain Pipe
• How to Install Sink Compression/Shutoff Valves

Soldering copper pipes, also known as sweating them, is a straightforward task if you do it right. If you make a mistake, however, the repair can be troublesome and time-consuming, and it’s difficult to guarantee the results. One of the factors that makes the repair difficult is the presence of water. If even a little remains after you’ve drained the pipe, it prevents the metal from getting hot enough for resoldering. Apart from that, you need to thoroughly clean the old solder off the old joint for the repair to work, and that isn’t always easy.

Turn off the water to the pipe you need to repair. if there is no dedicated valve for that pipe, turn off the main water valve.

Find a method to drain the line. If it’s on an upper floor, turning on a faucet downstairs may work. If it’s in the basement, there may be a hose bib outside that is below the joint you’re repairing. Leave the faucet open so that steam can escape. If you can’t find a suitable faucet, cut the pipe about a foot from the joint with a pipe cutter. You’ll have to repair it later by soldering on a coupling.

Heat the joint with a propane torch while you hold the pipe with a pair of adjustable pliers.

Pull the pipe out of the joint when the solder melts. This may take longer than you expect, because any residual water has to turn to steam and escape through the open faucet before the temperature will get high enough to melt the solder. Let the pipe and fitting cool for at least 20 minutes.

File the outside of the pipe and the inside of the fitting to remove oxidized metal and small amounts of solder. If solder has beaded on the pipe or fitting, melt it with the torch. This is faster and more effective than filing it.

Spread flux on the outside of the pipe and inside of the fitting when both have cooled down and you’ve cleaned them. Insert the pipe into the fitting and heat them with the torch. When the solder begins to boil, remove the torch and touch the tip of a coil of lead-free solder to the joint. Move the solder around the circumference of the pipe as it’s melting and wicking into the gap.

Let the pipe and fitting cool. Close the faucet that you left open or solder a coupling onto the pipe that you had to cut. Open the water valve slowly and check the joint for leaks.

To know how to desolder a solder joint is maybe just as important as knowing how to solder.

Sometimes you need to make a correction to your electronic circuit. Maybe you soldered a diode in the wrong direction or maybe two of your pads have accidentally been connected by some extra solder.

In these cases you need to know desoldering.

Desoldering with a solder sucker

Load the solder sucker by pushing down its plunger.

Heat the solder joint until you can see it is melting.

Place the tip of the solder sucker above the heated solder joint. Then push the sucker button to suck away the liquid solder.

Push down the plunger again to remove solder from inside the pump. Sometimes you will need to use a solder wick to be able to remove the last bits of solder if the pump don’t catch it.

Desolder using a solder wick

You can choose to use the wick from the roll or cut off a section and use it by itself. Cutting off a section is useful to avoid that heat gets transferred away from where you want it.

If you cut off a section, it can be smart to hold the section with tweezers. It can get really hot 😉

Start by putting the solder wick on the solder joint you want to desolder.

Put your soldering iron on top of the wick. After a few seconds you should see the solder getting wicked into the solder wick.

If the current section of the wick gets full of solder, cut it off and repeat the process until all the solder is gone.

Desoldering without any desoldering tools

If you don’t have a wick or a pump, you can still get by. This is not recommended, but might work if you’re desperate.

To remove an excess solder bridge between two pads you heat the solder joint then poke around with the tip of the iron until the bridge is gone.

To remove a component from a PCB you fasten your tweezers on the component lead you want to remove, heat the solder joint and then pull and jerk the lead out of the hole when the solder melt.

My favorite technique used to be the soldering pump. But I have found that when you are dealing with smaller pads and pins, a solder wick is sometimes much easier to use.

Reader Interactions

Comments

John Davidson says

desperate is right, i was starting to wonder why anyone would mess with desoldering after most of my fingers ended up with that nice golden color to them, be careful, or end up with chicken fingers

Gassan Ali says

February 14, 2020

It’s a nice lesson. What about electrical desoldering pumps? I’ve never used one, but I often see prefessionals using on YouTube videos. When they’re in action, they look efforless.