There are several ways to connect and seal metals and each method has its purpose. However, many people today confuse brazing with welding or even soldering and this may create problems. Whether it’s standard brazing or special techniques like stainless steel brazing, knowing more about the process can help you avoid common mistakes with metals.
What is Brazing?
Brazing is used to join metals together by melting another material into a joint between the two metals. The brazing material melts at a lower temperature than the metals to be joined.
What is Soldering?
When you need to connect two metal surfaces together but do not require an extremely strong bond, solder may be the answer. The material (called solder) is very soft and easily melted and acts as a bonding agent. For many years, solder was made mostly from lead, but environmental concerns are slowly changing the lead content in many things including solder.
What is Welding?
When two metals are welded together the literally melt to form a bond. This takes intense heat and often times a special welding electrode (containing flux) is melted
What Do They all Have in Common?
All three methods of joining metal use some kind of flux. Whether it is stainless steel brazing, soldering electrical components or welding steel together, flux acts as a cleaning agent to help create a bond.
The process of brazing and soldering does not actually melt the two pieces together, as with welding. Another material is used for bonding. Brazing is used for strong bonds and uses higher temperatures than the soldering process. Brazing can be used to join similar metals or completely different ones. With welding only the same metals can be joined. Because the process of brazing is more exact it can be used to join parts together with a high tolerance. This requires more skill than soldering because absolute cleanliness must be maintained throughout the process, to ensure a proper bond.
The skilled worker makes sure brazing temperature is as low as possible while still doing the job. This minimizes the effects heat has on the parts to be joined. It also makes it easier on the brazing equipment. Stainless steel brazing bonds metals across the areas to be joined. On the other hand, welding is made with an outer seam or joint.
The process of welding does not have to be as clean as with brazing because the very high temperatures can literally burn away contaminants. This is not the case with soldering or brazing due to the lower temperatures.
Each method has its benefits and it depends on the needs of the business, which process should be used.