Everything you need to know about soldering

What is soldering? 

Soldering allows metal components to be joined together. A so-called bonding agent is used for this, which can also be called solder or solder. Soldering is a relatively simple process. All that is required is a soldering iron and knowledge of its use and of metalworking. The material used to join components has the same physical and chemical properties as the elements in the metal group. This ensures a homogeneous appearance of the weld after the process is completed. However, the joints are visible to the naked eye. They resemble thickenings at the point where the parts are joined.  

Soldering versus welding 

Popular metalworking techniques can also include welding. Unlike welding, brazing is a process that allows components to be joined together without affecting their structure. It is performed at a temperature that will not overmelt or damage the components being joined together. The temperature produced by the soldering iron must be high enough to make the joint ductile. It is slightly higher than that needed to melt the solder, yet low enough not to damage the components being joined together.  

Types of soldering 

We can divide soldering into two basic types: 

• Soft soldering - temperatures below 450°C; 
• Brazing - temperatures above 450°C. 

These methods differ in the temperature used during operation. The soldering temperature depends on the solder to be used. The optimum temperature for proper soldering is about 30 to 50°C higher than the temperature at which the binder melts. This allows us to see the relationship between the type of soldering and the fusibility of the binder.  

For soldering soft We use solders with a melting point of approximately 400°C. This soldering is used for joining more delicate metals.  

For soldering hard whereas we will use medium-melting metals. It will be a good choice for more robust components.   

Soft soldering  

It is a method that is often used in households. The process is relatively simple and at a low temperature. It should not cause any difficulties. With this method, we can easily do it ourselves with the simplest soldering iron. 

Soft solder will be the right choice for joining parts made of steel, copper, brass or zinc. It can also be used to join parts made of the metal alloys mentioned earlier. This will ensure a precise and uniform joint. Ready-made soft solders can be obtained in several forms. We can find wires, sticks or even powder.  

Brazing  

To brazing The simplest soldering iron may not be enough. Then we will need professional tools. Experience in the trade may also prove useful. We can make solders whose temperature does not exceed 450°C ourselves. However, some metals require soldering temperatures that are up to five times higher. In extreme cases, we can already talk about industrial soldering. This is carried out by specialists using professional tools.  

The most popular hard solders are silver mixtures. With these, we can join most metals together. Copper-phosphorus ones will work well for joining brass, copper or bronze components. When brazing stainless steel, a nickel binder will work well. Using copper binder, we can join parts made of steel, brass and tin alloys.  

We can use brazing to join copper pipes. We can also use it in automotive or refrigeration applications.  

Preparation for soldering  

Before we start soldering, we need to remember a few things. The parts to be soldered should be properly aligned with each other, and the gap between them should be taken care of. This should be approximately 0.04 mm. Maintaining the correct distance between the parts ensures that the solder penetrates well into the materials to be joined and that the joint is consistent. To ensure that the soldering process is carried out without unnecessary complications, it is worth paying attention to the thermal expansion of the components. This is important because this parameter can vary depending on the type of metal used. Then all that remains is to clean the materials and degrease them. Any traces of corrosion, oil or paint are removed using specialised agents. Skipping this step will result in the flux and binder being unevenly distributed and the whole thing will not heat up to the same temperature. Worse still, the metal may then oxidise when heated.  

Selecting the right flux is crucial. We have solders available on the market that contain this chemical in them. The flux will make the soldering process more efficient. Next, we should position the parts we will be joining together in the most convenient way for us to solder. A good solution may be to place the parts on bases made of materials that will not conduct heat, such as ceramic.  

The soldering process should take place at the correct temperature. Only the parts to be soldered should be heated. When dealing with larger surfaces, a gas torch, for example, can be helpful to heat them up. Once the flux is uniform, we know that the components have heated up evenly. Now simply apply a wire of solder and hold until melted. This will allow the components to fuse together. If we run out of flux, let's not panic. We can add it at any time. This is even better, then the solder is smoother.  

What if the soldering doesn't go our way? 

When the process is finished, clean the soldered joint. While still warm, it is a good idea to immerse the components in warm water so that our flux will peel off. We can use a wire brush to remove any remaining binder.  

Soldering course 

A soldering course will be an excellent choice to learn about proper soldering with the knowledge put into practice while practising under the guidance of an experienced instructor. During such a course, you will learn, for example, how to choose the best soldering iron.  

During the training sessions, you will learn how to solder correctly and receive professional guidance to enable you to solder to a high standard.  

The soldering course is designed to give you the skills to produce solder that will meet the performance standards of your specific industry.  

Mastering the above steps will enable you to become a professional. During the course, you will also receive tips to avoid mistakes and be able to determine the soldering time. 

If you want to learn soldering and other techniques under the guidance of specialists. Take a look at our company's offer!