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Can You Weld Brass to Steel? What You Need to Know!

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brazing a steel bike frame with brass solder

Brass is one of the most malleable materials you can use in a welding process. It is essentially an alloy of zinc and copper and is popular as a base metal and filler material. It can be joined with other metals to create sturdy and reliable joints. But since the melting temperatures of brass and steel are different, welding brass to steel may prove challenging, but it is possible.

Brass is made from the fusion of copper and zinc, while steel is a strong metal often used in the construction industry. These metals can be fused to create brass steel. This is, however, a very complicated and dangerous process and should only be attempted by experienced welders or in the presence of a trained professional.

So, why exactly is it difficult to fuse steel and brass? What method is ideal for fusing steel and brass? What are the dangers and the safety measures you should take? Read on to find out.


Why Is It Difficult to Weld Brass to Steel?

The major problem associated with welding brass to steel is the temperature difference. These metals have different melting points. Brass will melt somewhere between 900° and 940° Fahrenheit, while low alloy steel’s melting point is 2,610°F and that of high alloy steel is 2,600°F. To fuse these metals, you have to heat the materials to the highest melting point before attempting to weld.

So, when welding the two metals together, the materials will get too hot and melt together. The heat produced during a welding process will likely create bubbling and outgassing, typical when heating materials containing a lot of zinc. This will in turn create a porous weld that is highly susceptible to cracking.

Also, you need to know the percentage of zinc in your brass. The percentage of zinc in both metals affects the melting point, which will consequently affect the weld. So, it’s imperative you know the amount of zinc in brass before you begin to avoid porous welds that are likely to crack.

The zinc materials also create problems in welding brass to steel because it reacts violently to environmental contaminants. You may need to get a shielding gas, such as oxyacetylene, to protect the weld.

Moreover, when zinc melts, it produces highly toxic fumes that can be detrimental to a welder’s health.

How Can You Weld Brass to Steel?

As you may have gathered from the above information, welding brass to steel is possible but not recommended. It is not only dangerous but not suitable because the process produces excessive heat that could affect the integrity of the joint or damage the metals.

In addition, different welding methods tend to affect the appearance of the steel. So, you need a method of fusing brass and steel to create strong and durable joints without compromising the weld and the welder’s health.

The popular methods used to fuse brass to steel are blazing and soldering. Let’s have a look at them.

Brazing Brass to Steel

Brazing is a metal-joining process where two or more metals are fused by melting or directing filler materials into a joint. In this process, the filler metals have a lower melting point than the base metal.

Unlike arc welding, blazing utilizes heat applied via furnace, torch, induction, resistance, or dipped heat sources at temperatures of 840°F. Arc welding, on the other hand, uses electricity as the main source of heat, reaching temperatures of up to 10,000°F.

During the blazing of steel and brass, first heat the base metals until they are hot enough, ideally red hot. Then the filler material is allowed to flow in the gap between the close-fitting metal parts through the capillary action. The filler material is then heated to temperatures slightly above its melting temperature while being protected from oxidation using a flux. 

For brazing to be successful, you need to create a suitable atmosphere for the process. You can shield your weld using noble gasses, inorganic vapors, ammonia, nitrogen, hydrogen, and a vacuum. Heating sources such as a furnace, induction coil, and a torch are also used in the process.

The molten metal is then spread over the base metal through a process referred to as wetting. It is finally cooled to fuse the workpieces to create brass steel, which is sturdy and durable enough for metal fabrication applications. Since the base materials do not melt, they tend to retain their physical properties.

While brazing, it’s essential that your welding be consistent. If the pace is too slow or the distance between the base metal and the torch is too small, you risk melting the base metal. You should also work from a ventilated environment to reduce the inhalation of the hazardous gas produced by molten zinc.

Brazing is a commercially accepted process used in a wide range of industries due to its high-quality joints and flexibility. It is also an easier alternative to fusing brass and steel compared to other methods. However, you need a lot of practice to get it right.

The 5 Steps for Blazing Brass with Steel

  1. First, use the wire brush or emery cloth to scrub the surface of the metal to remove layers of dust and rust. Then clean the surfaces using a degreaser or soapy water to remove any stubborn debris.
  2. Second, position the metal in the most comfortable position. In many instances, an overlapped joint is more suitable because it is stronger and fuses easier than a gapped joint. If need be, use clamps to secure the pieces in position.
  3. Third, heat the joint where the two pieces of metal meet until it glows red hot.
  4. Then, apply the brazing rod to the joint while still heating the metal surfaces. For larger surfaces, consider heating pieces of the joint to optimum temperature. Then proceed to the next adjacent area.
  5. Lastly, after brazing, use a wire brush to clean the brazed surface to remove any oxidation or welding residue.

Soldering Brass to Steel

Soldering is another widespread method of fusing steel and brass. When fused, these materials create Brass steel with an attractive appearance that is mostly used to decorate kitchens. Solders provide filler materials to make a flux that prevents joints from oxidizing during the soldering process. 

The method of soldering is similar to brazing but with one major difference. Soldering takes place at temperatures below 840°F while blazing occurs at temperatures above 840°F. 

To successfully fuse brass and steel using the soldering method, you can use silver soldering sticks. The most common silver solders with applications in the welding world are SSQ-6, SSF-6, and Super Alloy 1

The 6 Step Soldering Process

  1. First, thoroughly clean both metal surfaces to remove any traces of oxidation and debris from the surface of the metal. The tools you can utilize for this step include sandpaper or a wire brush. If you are soldering smaller components, you can also use a wire to create a sizable gap between the joint and the welding surface.
  2. After cleaning the metal surface, proceed to clamp the metals together in preparation for the process. Ensure that they fit together as closely as possible because the tighter they are, the better the grip. This is an important consideration because the solder acts as a glue, so if the gap is too large, your solder will not hold.
  3. After you have prepared the base metals, you can then apply the flux where you want your solder to flow. Flux holds the pieces together for soldering. You can use a brass soldering flux, which is tin-based. Make sure that the metals are properly clamped together and positioned at an angle that allows the flux to flow naturally through the capillary method. You can also use a paintbrush to spread the flux.
  4. When the flux is in position, use a propane torch to heat both ends of the joint. Welding experts recommend applying the most heat to the thickest side of the two metals. Continue heating until brass changes color indicating that it is hot enough.
  5. Before you apply the solder to the two joints, you need to first test the heat to ensure that it is hot enough to melt the solder. When it is hot enough, it will start to flow. Remember, that the solder always flows towards the heat source, so positioning is also crucial to avoid accidents or weak welds.
  6. After you are satisfied that the metals have evenly fused, you need to wait for a few minutes for them to cool down. Proceed to clean the surface using baking soda or water to remove any leftover flux. Flux can be corrosive to metals if not cleared off a welding joint.

Safety Measures When Welding Brass to Steel

Welding has always been a dangerous process of fusing metals. However, when working with brass you need to take extra precautions. This is because brass is made from an alloy of copper and zinc. 

When exposed to extreme temperatures, zinc melts to produce toxic fumes with adverse health effects on the welder and people in the immediate environment.

So, when welding brass to steel plates, ensure that you are working in a properly ventilated environment. Also, ensure that your welding helmet is sufficiently ventilated as well.

In addition, zinc tends to spatter when in molten form. The bubbling will likely throw some of the molten metal on your face and skin. Therefore, besides wearing a helmet, ensure that you have protective gloves and boots when working with brass.


Conclusion

Welding brass to steel is a complicated process even for the most experienced welders. This is mainly because of the temperature difference in the melting points and the health hazards involved. It is however not an impossible endeavor. 

You can use the brazing and soldering process to fuse steel to brass. The brazing method is more popular because it uses heat treatment to produce clean and strong joints and is ideal for industrial applications. Soldering on the other hand is a less popular option but can create filler material sturdy enough to create strong joints.

These methods are not entirely hard to use if you follow the instructions. However, ensure that you have safety measures in place to minimize the risks of welding-related accidents.


Featured Image Credit: Philipp_Konietzko, Shutterstock

Cameron Dekker
 

Cameron grew up in Allentown, Pennsylvania, a once-proud steel town on the Lehigh River, where he got a taste of TIG welding in his high school shop class. He holds certificates for Certified WeldingEducator (CWE) and Certified Resistance Welding Technician (CRWT) from the American Welding Institute. His interests include scuba diving, sculpture, and kayaking.