Welding technology is very important in various places such as construction, vehicle manufacturing, and ship construction. In particular, TIG welding allows a strong connection between different types of metal. One metal that you can weld with this method is copper. Copper has many interesting properties and a cheap price. However, those characteristics that make it a popular material in many structures make it a difficult metal to weld. Here in this article, we shall discuss TIG welding of copper with other metals such as stainless steel, aluminum, nickel, and brass. We will also provide general guidelines that anyone who welds copper must be aware of.
- 1 Copper Alloys and TIG Welding
- 2 TIG Welding Electrodes on Copper
- 3 Important Parameters for TIG Welds on Copper
- 4 A/C or D/C? Polarity Settings for Welding on Copper
- 5 Recommended Amperage on Copper
- 6 Shielding Gas in Tigging Copper
- 7 How to TIG Weld a Copper Pipe
- 8 Step-by-Step Method
- 9 What’s the Weldability of Copper to Steel or Stainless Steel
- 10 How TIG Welding on Copper to Brass Works
- 11 How to TIG Weld Copper to Nickel
- 12 Tig Welding Process on Copper and Aluminum
- 13 A Few Words About TIG Welding
- 14 Final Thoughts
Copper Alloys and TIG Welding
There are many different kinds of copper alloys found around us. From all those alloys under the right conditions, a welder can perform strong TIG welds. However, you must keep in mind that settings and conditions where the process takes place might change vigorously when compared to TIG welds in metals like steel. So, a welder must first try to analyze the various types of copper found and then after finding out that the welder must learn the different types of setting followed for those metals. In this article, we shall see the various copper alloys at first and how to effectively weld them with other metals such as the following ones.
- Steel and stainless steel
- Brass and bronze
Obviously, there are many other Copper alloys available on the market. However, it is not difficult to determine the right settings whether you weld pure copper or a metal that contains other elements.
Now when we talk about TIG welding settings, a very important parameter is the percentage of copper inside the metal. However, the thickness of the metal is still the most important factor. can be classified as thick copper alloy and thin copper alloy.
When a welder uses tig welding in thick copper he must preheat the copper alloy up to 350 degrees Celcius. For example, an inch thick sheet of copper must be heated at 60 degrees Celcius. On the other hand, a 5-inch thick sheet must be preheated at about 400 degrees Celcius. Actually, the preheating temperature and current will be less as the copper alloy is less thick. Also, the welding current that could be as high as 350 Amperes. So, the very important first step is to consider the thickness of the alloy. Now let’s see some other parameters of TIG welding on copper.
TIG Welding Electrodes on Copper
Before you start your welding project on copper, you must take into account of electrodes. The right choice of welding electrodes is extremely important for TIG welding on copper. Here are the most commonly used electrodes for such projects. We have options for AC and DC current. Keep in mind that you can use the same electrodes for plasma welding projects
2% EWTh – 2/WT20 (RED)
The main oxide here is 1.7 to 2.2% thorium oxide. It is considered to be radioactive in nature and it is said to be the best one for direct current applications. You can use such an electrode with transformer-based power sources. Also, it is efficient for non-corroding steels. That’s why I would highly recommend them for most TIG welding projects on copper alloys.
0.8% – EWLa – 8/WZ8 (white)
The main oxide that can be traced inside the rod is 0.7 to 0.9% Zirconium oxide. It is non – radioactive and it is best for alternating current AC. It is applied to copper alloys and other metals like aluminum, magnesium, and steel. Here inverters or sometimes transformer-based power sources that have as an output constant amount of current can be used with those electrodes. Actually, you can use higher amperage and still control have better control over the weld pool in comparison with ones made out of pure tungsten. Moreover, you will also notice less spattering between those two types of rods.
These are commonly used electrodes in TIG welding projects. Keep in mind that there is a great variety of rods and many other types work great with copper and its alloys. So, you will probably have excellent results with these rods but still, a detailed survey has to be made if you want the optimal performance for your specific project.
Important Parameters for TIG Welds on Copper
When we talk about the important parameters of TIG welding, the first thing which comes in everyone’s mind is currents, electrodes, and more. Before diving deeper on these topics I would like to mention something. Most people forget about the proper use of PPE. PPE stands for Personal Protective Equipment and the use of it is mandatory for any welding operation.
I know that most of you have been tired of hearing the safety first rule. Also, many welders use are not taking all the safety measures required. However, I must insist on taking proper safety measures in all welds especially the ones that you are uncertain how it will go.
Chances are that if you are reading this then you are not familiar with welding on copper. You might use too much current and have a lot of spatter in comparison with welding on steel.
So, please don’t disregard safety measures especially if you are experimenting. That includes gloves, helmets, and special clothing.
Since I talked about safety let’s see what you need to know about the other equipment involved in TIG welding projects on copper. Keep reading if you want to find more about the process and avoid making any flaws.
A/C or D/C? Polarity Settings for Welding on Copper
A welder may use one of the two types of current for his welding operation. Those types are:
- A/C or Alternative current
- D/C or Direct current
Current settings may be difficult to be established on metal other than steel. When it comes to copper and its alloys a very important parameter is the amount of copper inside the metal. While talking about the polarity, D/C the direct current has two polarity types. DCEN or direct current electrode negative and DCEP or direct current electrode positive are those two polarities widely used.
As I have written in a previous article, the difference between DCEN and DCEP is the direction of the current. The electric current runs through a closed circuit. However, that’s not enough since there has to be a power source that allows the creation of two poles.
In DCEN the negative pole is on the side of the torch while in DCEP the negative pole is on the side of the metal. Most TIG welders choose the DCEN setting when it comes to welding copper. DCEP is rarely used with copper. As an alternative to DCEN, you could use A/C but personally, I wouldn’t recommend it.
Now let’s talk about another important factor that plays a vital in the quality of any weld.
Recommended Amperage on Copper
In most machines, the welder can adjust the amount of current by pressing a foot pedal. The foot pedal allows no current to flow at its resting state, and then it will increase very slowly when the foot pedal is pushed down to the needed limit. The amperage can also be limited by making proper settings in the tig welding machine. In other machines, there is no pedal and the amount of current is adjusted by a button or lever on the torch.
If it’s possible I would suggest making a test weld on a piece of copper similar to the one that you have to TIG weld. Increase the current by 30-50 Amps in comparison with the amperage that you would normally use for stainless steel. If the weld is not ideal then you should calibrate by lowering or increasing the amperage. Keep in mind that thicker pieces of copper might need a bit more amps. For example, a 4-inch piece of copper might require 350 amps while an inch thick piece of the same metal would require 150 amps.
Shielding Gas in Tigging Copper
There are various gases that are used for welding processes. and mostly two common gases are being used for TIG welding. It is
Argon gas is the most common gas and it is also considered as the best option for TIG welding on copper. Because argon gas is heavier in comparison with helium, the process runs more easily for the welder.
At certain times, argon gas is mixed with hydrogen and this mix of gases will give certain unique advantages. When adding two percentage of hydrogen to the pure gas which is argon it will be helpful to save the time of the welders and also it helps to save their money. However, I wouldn’t use such a mixture in welds with copper.
Apart from that instead of using hydrogen, nitrogen is also used for mixing with argon. It also gives excellent benefits in certain scenarios. For example, an argon-nitrogen mixture increases the weldability of copper at high amperage. With the right regulator, you can easily create such a mixture. Also, the argon/helium mixture is extremely popular in operations with copper as the base metal. So, it’s up to the welder who can make use of these two options whenever needed.
When it comes to pure helium, which is entirely different from argon, the welding process might become harder for the welder. Therefore I would avoid using it.
To sum up, I would recommend the use of Argon, Argon/Helium mixtures (even rich in helium), and argon-nitrogen mixture for TIG welds on copper.
How to TIG Weld a Copper Pipe
Tig welding done on copper pipes is very beneficial and it provides rigidness extensively. Many prefer soldering technique than using tig welding. However, TIG welding is a much preferable technique for creating lasting strong connections on copper pipes. Let’s see in the following video the right technique for making such a weld.
Many of you might get confused with the information that I give you in this article. That’s why I decided to create a plan for making TIG welds on Copper So, here is a step-by-step methodology for creating strong connections with copper as your base metal.
First Step: Take Safety Measures
The next is that a welder must be very conscious of his safety in order to prevent risks. It is a must to make use of all personal protective pieces of equipment. Helmets, gloves, protective clothing, and proper ventilation are very important. Please don’t neglect proper ventilation because fumes that come off TIG welds of copper can be very toxic. So, performing the process in an open area or in a room with machinery that sucks the fumes is highly recommended.
Second Step: Preheating & Assembly
The first two actions that a welder has to pay attention to are the preheating and assembling processes. It is extremely important for both pieces of copper to have the right temperature before welding begins. In most cases, at first, the welder preheats the copper and then he assembles the pieces. However, in some cases like not being able to make the weld immediately after preheating is completed, the order of those processes is reversed. That happens because we don’t want copper to cool down.
Let’s see how this process would normally go. At first, the welder has to perform a preheating process because of the high thermal conductivity of copper. The segments of the pieces of metal to be joined must be preheated at first in a uniform manner. This helps to dissipate the heat gradually and this in turn reduces the probability of cracking. The preheating temperature depends a lot on the thickness of the metal. Mostly 50 to 752 degrees Fahrenheit is the temperature range where welders use depending on the thickness of the sheet. Here is a table where you can notice the preheating temperatures for pieces of copper with different thicknesses.
|1 in||50 °C or 122 °F|
|2 in||75 °C or 167 °F|
|3 in||135 °C or 275 °F|
|4 in||210 °C or 410 °F|
|5 in||360 °C or 680 °F|
Once preheating is completed then the welder is almost ready to begin the process. Therefore, the required copper pieces, copper joints, and also copper fittings are assembled. I wouldn’t advise a welder to take his time because the copper might cool off too much. However, this doesn’t mean that he has to be hasty on making the assembly. That’s why some welders assemble first and preheat afterward. Either way, the order probably wouldn’t make a difference.
You can use clamps for making the assembly of the pieces. It’s a good way for keeping everything nice and stable.
Third Step: Machine Settings
This is a small step but it is the one that most welders have the most questions. It’s the current settings that they will use for their process. Despite the fact that TIG welders with advanced settings are not expensive, we can safely say that your TIG welder has at least three settings, DCEN, DCEP, and A/C. I recommend DCEN with 30-50 more amps than those that you would normally use on TIG welds. Here is a table that will give you an idea of what amperage should work. Keep in mind that you will probably have to calibrate the amperage on copper alloys because the metals of the alloy affect its properties.
|1 in||160 amps|
|2 in||260 amps|
|3 in||300 amps|
|4 in||340 amps|
|5 in||360 amps|
Fourth Step: Perform the Weld
When the required temperature is obtained and all the settings on the machine are selected, the welding process can be initiated. A molten puddle is being introduced and then the filler is inserted in the seam. The wire of the filler has to be introduced immediately after the appearance of the puddle. This action is essential to happen quickly in order to avoid oxidation.
Ventilation and Shielding gas
A key aspect of the whole process is using a shielding gas. You can use argon, helium, and in some cases mixtures of argon with nitrogen. Also, since the fumes from copper can harm your health, it’s a good idea to weld in open spaces or with good ventilation systems near the seam.
What’s the Weldability of Copper to Steel or Stainless Steel
It’s not so uncommon to use copper with steel in metallic structures. So, many welders will doubt whether copper and steel can be welded together or not? And the assured answer to this question is “YES”. Before reading out what you should do in such a welding job let’s see whether TIG welding is a good method for it.
Is TIG the Best Choice
TIG along with MIG and stick welding are the methods that dominate. So, a very good question is which of those methods is optimal for making welds on copper to steel seams. The truth is that TIG is a great method for such a weld. There many reasons why this is true for so many operations on dissimilar metals. Let’s see the problems of combining steel and copper with welds.
- Firstly, both the metals substantially have two different points of melting. Stainless steel will have the tendency to melt at about 1400 degrees Celcius. However, copper melts at about 1085 degrees Celcius. This 315 degrees Celcius difference in temperature can create many problems. And in welding operations, a lot of heat is produced near the seam.
- The second reason is that there is a major metallurgical problem Both of these metals are extremely dissimilar at a microscopic level. Stainless will not be fully soluble when it is being mixed with copper. This could be a cause for a weak connection between those two metals.
Those problems seem difficult to overcome because they are related to the inherent properties of those metals. Despite this fact, if you make the TIG weld correctly there will not be any important problem. Let’s see what you should do in a case like this.
Tips for Strong Welds Between Copper and Steel
Before starting the welding process, let’s make a list of what you will need.
- 1/16” silicone bronze rod
- Argon as a shielding gas
- Sharp tungsten electrode head
What Changes in the Procedure
The very first step which all must follow is to clean the parts thoroughly which are to be welded. In every welding operation, the seam must be clean. However, in this case, it is more important to have everything clean in comparison with TIG welds between two pieces of steel. Also, you will provide a nice finish to your work.
This cleaning process can be done with the help of two different objects. You can use a brush and a ball of steel wool. Using these two tools will be really useful for cleaning the parts as it helps to complete the process quickly and neatly.
Assembly and Process Tips
Assembling is very important because any mistake can cause a collapse during the welding process. You can reduce the risk by using clamps. Also, you will be able to place the pieces of metal exactly where you want.
Then after assembling, the argon gas can be turned on. You can use the DCEN current setting. By using a sharp tungsten electrode the process begins. The heat which is passed on the copper has to be keenly observed and then slowly start adding the rod material into the pool. There is no need to heat up the steel piece a lot because it may create structural cracking.
After completing the welding, check if there are any imperfections by thoroughly cleaning out the area with the help of a brush and also make sure that there are no leaks.
How TIG Welding on Copper to Brass Works
A very unique case of welding is the one between copper and brass. Many welders have questions about this scenario and I couldn’t forget mentioning it.
It’s difficult to weld brass because it contains a lot of zinc which melts at a low temperature of 907 degrees Celcius in comparison with other metals.
Brass is a metal that tends to be generic and it covers a very wide range of copper alloys. It’s a combination of copper and zinc. The concentration of copper inside the metal greatly affects its properties.
That’s why brass has a wide application with both the commercial and also non-commercial industries. Brass is sometimes used in the decorative pieces of many households. Many pieces of jewelry have brass. It gives them more texture and enhanced appearance.
Guidelines to Remember Before Starting
Here is a list of a few tips to remember the given points for connecting effectively brass to copper with welding.
- Grounding of the tungsten electrode to the tip. Make sure that the tip is not blunt
- Try to keep the heat on the base metal and avoid keeping it on the weld metal.
- Maintaining a constant travel speed is very much important
- Dirt can create big problems, clean the seam thoroughly. Acetone could make wonders in a case like this.
- Hold upon the equipment at the proper angle of 15 – 20 degrees away from the direction of travel
- Do not allow the tungsten to touch the workpiece
- Use effective ventilation, fumes can be toxic
- Try to be consistent with the welding process
- Don’t preheat brass at a higher temperature than 365 degrees Fahrenheit.
How to TIG Weld Copper to Nickel
Next, we shall discuss some tips on how tig welding should be done when the two metals that have to be connected are copper and nickel. Those metals have very good weldability. Therefore, if you keep reading you will understand that TIG welding with those materials is trouble-free.
Nickel and TIG Welding
A TIG operation that involves copper and nickel gives high flexibility because the heat input given through the arc and the filler gets separate control. So, in this manner, it will be more flexible than other methods and in all thin-walled pipes, this simple method can be adopted. Let’s see some tips that you can use in such a scenario.
- The material which is been used as the filler has to be incorporated precisely. Also, a simple fusion of the given base metal should be avoided
- Mostly argon is considered a suitable gas for shielding purposes in this scenario.
- The arc used in the process must be kept short so as to ensure that the gas shielding is protecting the welding pool adequately enough.
- Direct current will be the best suitable option because it sheds current uniformly so as it will be helpful to complete the process excellently.
Tig Welding Process on Copper and Aluminum
Tig welding on copper to aluminum will need a shielding gas which can be usually argon as it is been used widely on many occasions. Also, argon will be efficient enough to give an almost perfect result.
The surface must be cleaned thoroughly so as done in all other welding processes between dissimilar metals. Sometimes oxides may be accumulated on the surface of the metal and so care must be taken while cleaning the area near the seam. That is because these oxides will melt at a higher temperature than the one of aluminum. Therefore, this is the reason why cleaning has to be done perfectly.
In TIG welds between copper and aluminum, it will be best to use A/C. Alternating currents at a very high frequency will acquire the best result in this welding scenario. The filler metals for this type of welding must be in high quality and it is crucial that they are not contaminated.
So, these are the factors that you should take into account when you tig weld copper with aluminum. There are not many variations in comparison with the standard method that I provided for most copper TIG welding operations.
A Few Words About TIG Welding
In case you are not familiar with TIG welding, let’s have a small reference into the basics of TIG Welding. That’s because some of our readers are beginners and might be confused later in this article.
TIG is briefly called Tungsten Inert Gas and the principle adopted here is that an electric arc is created between the metals and the electrode. With the help of electric power supply both pieces of metal along with Tungsten melt.
Benefits of TIG Welding
TIG welding is a very popular method among welders. The benefits are practical and in some cases, aesthetical since it is not uncommon to incorporate beads as part of the design. However, control and precision over the metal can be obtained easily in TIG welding. Whatever the shape of the objects is like such as round or odd, tig welding sticks can create firm connections on various types of base metals easily.
Also, the ability to weld extremely dissimilar materials is possible with tig welding. These two are certain pros and also there are various others which can be enjoyed while indulging in the process practically.
Process and Parameters of TIG Welding
In TIG, with the help of an arc molten tungsten creates a small pool that allows the connection of the metals. While the welder is working he will hand – feed the thin wire of the filler to the base metal. Then the molten pool solidifies as this process takes place the welder slowly moves the electrode along the seam. It’s all about the technique, speed, and voltage. In some welding operations, special electrodes are used. We will reveal more about these parameters later in this article.
During the entire process, a so-called shielding gas is used. It’s an inert gas that protects the area of the weld pool from contaminants due to oxygen transmission. The welder will get a completely finished product which will be a slag – free welding seam. This seam usually is as corrosion resistant as the base metal.
Many types of such gases may be used in TIG welding operations. However, the most common of those gases is Argon.
Many say that this process is deeply similar to oxyacetylene welding. That’s because both of these processes use a filler material for reinforcing the connection of two pieces of metal.
When it comes to types of materials that you can weld with the TIG method, there are few restrictions. The list of those metals is quite large. In that list, stainless steel, and so many other metals which are non – ferrous are included like Aluminum, Magnesium, and Copper alloys.
A welder who has more experience and extraordinary skills regarding this process can perform difficult welds on metals like brass.
TIG Welding Equipment
Without getting into very great detail we will mention some of the equipment that is used in this type of welding.
Welding machine: This is the power source in the entire process and the power supplied here will give constant current in forms of DC or AC.
Torch: This is been designed for automatic operation in order to deliver the heat constantly required for work.
Welding lead: It’s the cable that supplies electrical power to the tip of the torch.
Work lead: The very next item will be the work lead. It is basically a ground cable that is attached to the base metal with a clamp.
Ceramic Cup: You can place this object on the torch. It affects the properties of the arc.
Copper collet: This copper collet helps to catch and hold the tungsten electrode. and then it will be helpful for adjusting the entire length of the tungsten which protrudes from the given cup.
Shielded gas supply: The gases used here will be helpful enough to protect the entire welding area from the gas in the atmosphere which may create defects involved. Mostly all welders will make use of 100% argon and even some may use argon gas mixture along with other gases.
Hence we have completed our discussion by mentioning several important points about TIG welding of copper with other metals. A very important part of the article has to do with safety. That’s why I have to emphasize the importance of PPE. The hidden risk when dealing with copper and its alloys are the fumes that are released during the welding operation.