When you start your welding journey, the terminology can be overwhelming. There are so many types of welding and applications that it’s easy to get your wires crossed.
Even some seasoned welders have trouble differentiating between the various types. So, it’s completely normal for you to ask, what is braze welding?
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Let’s take a look at this method of metalworking and what you can use it for. We will discuss the difference between braze welding and brazing further in this article.
What Is Braze Welding?
Welding is one of the basic processes of any metal working. It revolves around joining two or more pieces of metal.
A common way to do this is through brazing. It’s a type of MIG/MAG welding that involves connecting metallic pieces using a filler.
You heat the filler until it reaches its melting temperature, then you pour it over the joint. At this point, it’ll start to flow through the gaps between the metal parts.
Once the filler covers the entire area, you let it cool and solidify. This filler provides a stable, strong connection that doesn’t require much shaping. In addition, the joint should be leakproof.
The brazing process is similar to soldering. However, with braze welding, you work with higher temperatures and closely packed parts.
Braze Welding Process
Even though the term braze welding sounds complex, the process is quite simple. If you stick to a few straightforward steps, you should be able to master the skill in no time.
Before we jump into the brazing process, there are a few safety precautions to take. Remember, you’re going to be working with molten metal.
Therefore, you should always have your safety gear on. Moreover, your workspace should be well-ventilated with a clear exit route.
Once you gear up, you’re ready to weld. To start the brazing process, you can follow these steps:
-Pick the joint position. It should include a small space for the filler to flow through.
-Clean the parts where the metals join to remove any dust or oils.
-Choose your brazing alloy (copper, silver, or aluminum).
-Apply an even layer of flux over your metal pieces to avoid oxidation.
-Clamp your workpieces together in the position you wish to join them.
-Heat the metallic pieces to the melting temperature of the filler.
-Slowly add the filler metal to the joint.
-Let the filler completely solidify.
-Immerse the joint in water to remove any excess flux.
-Polish the joint with a fine emery cloth.
Choosing the Brazing Filler
The only tricky part of this process is choosing the brazing filler. There are many metals you can use, but the most common are silver, copper, and aluminum alloys.
This is likely because these metals are widely available and have low melting points.
Depending on what metal pieces you plan on joining, your choice of filler will change. The rule of thumb is you want to make sure that you pick a filler that has a lower melting point than your base metal.
Braze Welding Techniques
This welding process encompasses different techniques. That means there are a few ways you can go about brazing.
Torch Brazing
One of the most common types of brazing involves using a torch.
You heat the metal pieces with a blowtorch until they reach the desired temperature. This technique works amazingly well for small projects and minor joints.
Its popularity comes from the fact that it’s simple to use. All you need is a torch and a little patience. That means torch blazing should be easy enough to attempt in your workshop.
Cast Iron Brazing
Cast Iron welding is also another type of brazing. However, instead of using a traditional heat source, this method relies on electricity.
You connect the cast-iron rod to a power source, then touch it to the joint. At the point of contact, the temperature will rise and melt the filler.
This method is excellent if you’re using a base metal with a high melting point.
Furnace Brazing
As you can guess from the name, this technique employs a furnace. It involves heating the metal pieces in a forge until they reach the temperature you’re looking for.
This process is much faster than torch blazing, which makes it ideal for larger projects and speedy jobs. However, you do need an industrial furnace to use this technique.
Moreover, you’ll have to take more safety precautions.
Vacuum Brazing
This method consists of carrying out normal brazing techniques inside a vacuum chamber. The main advantage of this is uniform temperature changes.
That means all parts of your workpieces will heat up equally and evenly. For this reason, the joints are more stable and extremely clean. What’s more, since there’s no air, you don’t even have to use flux.
However, this process is more dangerous and expensive than traditional brazing techniques. You’ll have to work with high temperatures under the intense pressure of a vacuum.
Braze Welding Advantages
There are many reasons why braze welding is such a popular process. Some of these include:
The method can create strong, long-lasting joints.
It requires a much lower temperature than other traditional welding processes.
You don’t need to melt your base metals and risk deforming them.
The joints are easy and simple to make.
The brazing doesn’t require you to heat your entire metal piece.
Braze Welding Disadvantages
Even though a large group of people favors this process, there are a few disadvantages to it. These include:
Risk of discoloration due to uneven heating.
Joints are highly sensitive to any temperature changes.
Joints can be slightly weaker than other traditional welding processes.
Braze Welding Applications
Once you consider all the pros and cons of brazing, you’ll realize that it’s more suited for specific uses.
Some of these applications include:
-Domestic tools and heat exchangers
-Light fixtures
-Metal fittings for furniture
-Musical instruments
-Relays and generators
Braze welding vs brazing: What is the difference?
Brazing is done at a lower temperature than braze welding. This means that the base material won’t melt when you braze. The base material does melt when you braze weld. Brazing requires that you clean the base material before you start.
If you want to braze, you have to warm up the entire fitting. Braze welding generally only heats up a part of the fitting.
Plumbers often braze copper lines. This means that the copper itself won’t melt but the material that is used to connect the copper does melt.
Brazing may actually be considered a high-temperature type of soldering. As with soldering, a molten metal alloy forms the joint between the two original workpieces. It is often used by plumbers to connect copper pipes. More modern techniques don’t require brazing as there are copper fittings that can be pushed together.
The filler metal is usually heated above 840 °F. This temperature is traditionally above the filler metal’s melting point, but still not high enough to soften the workpiece metal.
There are multiple heat sources to use in brazing:
Localized heating using a torch
High-frequency induction or high resistance electric current
Diffuse heating using furnace brazing or dip brazing
Due to the high temperature at which the filler metal is heated, the filler needs to be protected with a flux.
Since brazing requires less heat than welding but produces stronger joints than soldering, it’s a reliable joining method for most materials, including electrical components and pipes.
Advantages
-Less chance of damaging the original parts
-Stronger joints than soldering
-Can fuse dissimilar metals
-Doesn’t require post-heat processing
Disadvantages
-Produces joints weaker than welding
-Fluxes may have toxic components
-The produced joints have a different noticeable color
-When to Choose Soldering, Welding, and Brazing
Wrapping Up
What is braze welding? It’s a process people use to join two or more metal pieces using a filler.
You melt the filler and let it flow and solidify over the joint. Depending on your project, this can be copper, silver, or aluminum alloy.
This technique can create long-lasting joints. Still, these connections are slightly weaker than other traditional welding methods.
