Learning How to Solder
In recent months, we’ve discussed the benefits of soldering when working with copper, brass and jewelry. We’ve even heard from some of our loyal shoppers and trusted friends about their recommendations regarding best practices, but we’ve also noticed a collective groan emanating from DIYers who don’t feel comfortable operating a soldering gun. At Online Metals, we understand that a new process can seem daunting, but as we all know from experience, the first time doing anything is the trickiest. Everything after that is a step in the direction of eventual mastery.
Learning how to solder is a breeze once you know the basics. Read more and see for yourself why learning how to solder is a life-long skill worth having. And, if done right, can save you money and energy in the long run.
What Is Soldering?
Soldering is the process of joining two items with an intermediary metal (solder). Generally, the two items being joined will be metallic in nature. For soldering, the filler solder will have a lower melting point than the materials being joined. This allows for joining to take place in a system in which unlike welding, the original work pieces are unaltered by heat.
What You Will Need
Since we’ll be covering the basics, we’re going to focus specifically on the types of equipment you’ll need to get your basic projects off the ground. In this article, let’s discuss learning how to solder on a circuit board, as it is a great way to gain confidence and experience without having to worry about the price of high-quality brass or copper.
Soldering Iron or Gun
If you’re trying to determine whether a soldering iron or a soldering gun is the right choice, consider the work at hand and whether or not you’ll need more wattage for future applications. For most work involving circuitry or lower output needs, a soldering iron is perfect and especially handy for the beginner.
Both iron and gun are used to provide the heat source needed to melt the solder, and lower-end tools generally run in the 15W to 30W range. This wattage range is great for basic work, with 15W being adequate enough for hobbyist work with circuitry and electronics. However, the downside of lower wattage is the lack of power needed to join larger components or wiring together.
As you gain confidence in your soldering abilities, a 40W iron is a well-rounded tool allowing for faster heating and quicker joints. We believe that by using a higher-powered tool, you save more time and protect your work pieces from excessive heat being added.
Soldering guns typically range in wattage from 100 to 240W. Beyond working with heavy electrical components, a soldering gun can be used for lighter metals work in joining components. While the heat output from a soldering gun may be overwhelming for electrical work on circuit boards, the looped shape copper tip allows for great flexibility in movement over the working surface.
To compare soldering guns, checkout this soldering gun kit available on our website. You’ll see that the soldering gun has much more power than the iron. For more information about choosing a soldering iron, take a look at this article on Instructables.com.
When it comes to choosing the right type of solder, there are a number of options. Soft solders containing lead vary in composition of tin, allowing for variations in tensile and shear strengths but come with the downside of containing lead, which carries health and risks of birth defects. Recent changes allow for lead-free soldering where lead is replaced by silver, antimony and copper, with increases in the proportion of tin increased as well.
Flux-core solder is widely used for soldering circuitry and electronic parts as well as in metal mending and plumbing and can be found with relative ease. If you’re looking to solder electronics, rosin core flux solder is perfect in that it is non-conductive and is specifically designed to solder where flux residue cannot be removed. Acid core solder is used in plumbing applications and should never be used where electronics are present as the solder will erode and damage your circuit boards.
For heavy-duty work, hard solders come in handy for brazing and have a higher melting point, perfect for joining metal materials that are unable to be welded. These alloys are copper-based and generally contain silver or zinc.
PPE & Safety
Above all, make sure to follow safety guidelines for your equipment as well as for the work pieces that you’ll be using as you learn how to solder. Since the flux in your solder will release fumes when heated, we suggest working in a well-ventilated area with eye goggles. Wearing a face mask along with having proper ventilation is also recommended.
If this is your first time learning how to solder, or if it’s your soldering iron’s maiden voyage, make sure to coat the soldering tip with a thin coat of solder. “Tinning” ensures adequate heat transfer between the tip and the materials that are being soldered and aids in the flow of solder.
Once you’re ready to begin, ensure that the gun/iron is warming up and reaches its full temperature. It goes without having to explain, but a hot soldering iron is a properly working soldering iron. , If your iron is new, this also comes in handy in making sure that any corrosion resistance coatings that came with the tool won’t cause performance loss. As you’re ready to apply solder, first fully coat the iron’s tip with solder – the more the better! Ensure that the entire iron tip is coated and once you’re positive of peak coating, quickly take a wet sponge and wipe off excess flux. Make sure you do this quickly to prevent flux from drying out and solidifying and voila – you’ve just successfully tinned your soldering tip. Doing this ensures that your iron or gun maintains superb heat transfer.
Learning How to Solder – Printed Circuit Board
Soldering a printed circuit board (PCB) is not only the most common task for a beginner, it’s possibly the most common soldering job in general. You can either pick up a basic electronics kit from a store or if you’re looking to save money (or better yet, fix something that could use the love), you can always find a broken electronics device ranging from an old TV remote or a video game console, dismantle it and use it as your own test subject.
Step 1: Prepare the Surface
Before performing any work on an aged or exposed surface, make sure to start with a clean surface. If you want a low resistance solder joint that can hold up (and you do), then we suggest using an industrial cleaning pad (Scotch Brite, for instance) to remove any tarnishing while keeping the PCB secure. Once you’ve cleaned the board of its gunk and have nothing but shiny copper, feel free to use acetone to loosen up remaining deposits or chemical residue and cap it off with fresh air (or compressed air) to dry the board off and get rid of any final “floaties”.
Step 2: Placing the Components
If you’re working with an old board or are replacing a component, you’ll need to remove the old solder from the board first. Use a solder sucker (desoldering bulb) and heat the old solder up first, carefully removing the old solder as it softens. If solder is caked in there, a small drill bit can help at low speeds. Make sure to not damage the connections on the board or you’ll damage the circuits.
If you’re looking to place multiple components onto the board, we recommend starting with small/flat components first such as resistors and diodes, then moving to the larger capacitors and transformers. This ensures an even work space and less time spent handling sensitive components. Simply place the component’s leads through the PCB and either bend the tips at an angle or hold them in place with masking tape. You’re now ready to apply solder.
Step 3: Apply Solder to the Joint
First step is to get the solder iron and component lead heated up. Once you’re good there, apply solder. Touch the tip of the solder to the component lead, but not the tip of the iron. If your iron/gun is hot enough, solder should begin to flow around the lead and bubble up by the joint, emitting smoke (which is normal). Continue adding solder until the pad is completely coated and the solder forms a mound – not a ball, a small mound with concave sides. Allow for the joint and solder to cool and solidify.
Step 4: Inspect and Cleanup
Once the solder and work space have settled, you should inspect your work. Trim excessive leads with small cutters and if possible, clean up excessive flux from the board.
Learning to Solder: Practice, Practice, Practice
Learning how to solder takes time and patience. If you take what we’ve offered and conduct your own research, you’ll find that going from a beginner to a capable solderer simply requires time, education and practice. By continuing to practice, you’ll find that your speed and quality will greatly improve and your work will go from being acceptable to being the kind of output that shows value and skill.