Brass is the generic term given to copper and zinc alloys. Welding brass can be a little tricky as the amount of zinc composition significantly affects the melting point. Brass is frequently utilized in low friction applications such as decorations and musical instruments. Keep on reading to find out how to weld Brass.
Brass usually has a melting point within the 900 to 940 degrees Fahrenheit range, which makes it easier to cast using multiple methods. You can silver solder, as well as MIG and TIG weld brass successfully, giving you a variety of options. However, you need to take care that you choose the right shielding gas as the material can develop porosity and crack when the alloys separate.
Uses of Brass
Brass features properties like electrical conductivity, hardness, corrosion resistance, thermal conductivity, and machinability that make it highly desirable. Because it is a low friction material, it is often used in fittings and tools to be placed near flammable or explosive materials. It is also used in a variety of electrical and plumbing applications, as well as ammunition casings and valves.
Its bright gold-like appearance makes it a popular option for decorative use. It is used extensively in musical instruments that require high workability and durability.
How to Weld Brass to Brass?
Brass is not the easiest of materials to weld. However, we can help you make it a breeze if you follow a few simple steps.
Before you begin welding, make sure you find out the zinc percentage in the material you are dealing with. Doing so is particularly important in creating successful welds as Zinc has a lower melting point than Copper. Overheating the alloy can lead to porous weld and cracking.
Use Oxyacetylene gas to shield the material from the atmosphere effectively. Zinc, in particular, reacts aggressively with the environment and releases toxic fumes. Ineffective shielding can also produce porous welds, which become a major cause of rejection.
You will need to use flux to promote the fusion of metals better when working with Brass. To do so, you will mix the flux with water to create a paste. Then you need to coat the brass surfaces that you are welding with the flux paste. Make sure you use a braze flux that is specially designed to work with Oxyacetylene gas.
Create a barrier by keeping the acetylene gas on low and increasing the oxygen supply. Doing so will ensure that there is enough oxygen to develop a coating on the Brass. The coating prevents any harmful fumes from escaping during the weld procedure.
When welding Brass to Brass, make sure you choose a welding tip that’s larger than you would for welding brass to steel. You will need higher heat conductivity for the former procedure.
MIG Welding Brass
When using the Metal Inert Gas welding procedure for Brass, you need to take extra care when choosing the right filler wire. Using the wrong filler metal can result in a discolored weld, which is unacceptable by industry standards.
Copper and Zinc are the two main components of all brass materials. The ideal filler wire for color matching is the CuAI8 for most MIG processes. It consists of Copper and features 8% Aluminum. It will not provide the perfect color match but is considered acceptable.
It is impossible to find perfectly matched filler wire for MIG welding. To do so, the filler metal will need to consist of a significant amount of Zinc. Because of high arc temperatures, the Zinc will burn out, ruining the entire weld process.
To MIG weld brass, you follow mainly the same rules as are typical for the weld procedure. You will need to use a shielding gas that composes of Argon and CO2 or pure Argon. Using a 75/25 mixture of Argon and carbon dioxide gives you ideal results.
The absence of sufficient shielding gas will cause Zinc to vaporize, producing Zinc Oxide when heated. The newly formed gas will escape in the form of Toxic fumes not suitable for the welder.
To reduce the production of Zinc Oxide, welders recommend that you keep the weld area short. You could do so by opting for the stitch welding technique instead of making one continuous joint. Doing so gives the molten weld puddle some time to cool off by ensuring that the material is not exposed to constant heat for a long time.
TIG Welding Brass
Brass as a material has high levels of thermal conductivity. The Zinc in the material has really low melting points. Often during TIG welding, molten Zinc boils and jumps over to the electrode, which could halt the entire process.
To effectively TIG weld brass, we suggest you use an AC power inverter with 30-second pulses per second. We recommend you use the minimal amount of heat required to get the weld puddle going. You should take the heat off the material every few seconds to observe the pool. Doing so ensures you do not end up overheating the base metal.
With TIG welding, the joint produced is not very pretty. You will need to machine it off to ensure that the final product doesn’t look as ugly. After you finish welding, make sure you keep the heated area protected under Argon. It will allow the metal to cool off completely. If you expose the heated material to the atmosphere, it can cause porosity ruining the joint.
Use CuSn6 welding rods to obtain the best results in terms of color coordination when you TIG weld copper and zinc alloys. The result will not be an exact match. However, it is the closest you can get.
When MIG and TIG welding brass, it is next to impossible to obtain the ideal color match. If the color is essential, then we suggest you opt for a flame welding technique instead.
Flame Welding Brass
When flame welding brass using a CuZn39Sn filler wire gives you the best result in terms of color. There are three primary flames that you can use when flame welding.
Neutral
A neutral flame has no chemical effect on the workpiece.
Carburizing
A carburizing flame is unsuitable for use on metals that absorb carbon as it produces iron carbide. Such a flame will cause a chemical change in steel and iron.
Oxidizing
An oxidizing flame carries more heat than the other two. It is ideal for use on Copper and Zinc, making it the perfect choice for welding brass.
Flame welding brass is trickier as it requires you to keep a constant eye on the molten puddle. You will continuously monitor the effect of the flame on the material to determine the amount of excess oxygen needed for the procedure.
Safety Equipment
Because Zinc might sizzle and spatter, you need to wear protective boots to and gloves to ensure you do not get burnt. With Brass, you run the risk of toxic fume formation, which is why you should use a fume extractor to help keep you safe from harmful gas emissions.
Make sure you wear an excellent auto-darkening helmet with proper air ventilation when MIG or TIG welding. The arc produced in these procedures is very bright and can cause permanent damage to the eye if you do not take care.
Is Brass easy to weld?
Brass is not easy to melt because of the presence of Zinc. Zinc melts faster than Copper and other elements present in the material. Molten Zinc reacts with the atmosphere to produce zinc oxide, which is very harmful when inhaled.
You need to be careful of the shield gas selection when welding Brass. Make sure you choose one that produces sufficient coverage and protection to the metal. Do not turn off the gas supply until the weld joint has cooled completely for optimal protection.
Make sure you monitor the heat input continuously. Too much heat can ruin the base metal and cause the materials in the alloy to separate. All these technicalities make Brass a hard material to weld.
Can you MIG Weld Brass?
Yes, you can MIG weld brass provided you use an Argon and Carbon dioxide mixture as shielding gas. You will also need to use the right filler wire to ensure you get the closest possible color match. We suggest that when you MIG weld, use a stitch welding technique to be able to regulate the heat input.
Can Steel be Welded to Brass?
Due to the extremely different welding points, you cannot weld Brass and steel together as it becomes considerably tricky. You can, however, use the brazing technique to join the two materials together.
Brazing is a metal joining process in which you melt two different materials and combine them with the help of filler metal. With Brass and steel, you will need to use a silicon bronze filler rod.