TIG welding on copper is not very difficult, but it has some unique features compared to welding over other materials. Copper is an excellent conductor of heat and electricity, so you will need to take care of a number of things while welding. This article will define all those important factors for you.
Beginners usually find it tricky to join copper pieces. Copper also releases a lot of puddles which can harm your hands and affect your eyes. Welding on copper is different from welding on steel, but it’s quite straightforward and can be learned easily. After reading this article, you will be equipped with all the knowledge needed to start welding copper workpieces.
According to Freedonia, the demand for copper is expected to increase by 5% in 2021. The need for copper was 23.8 million tons in 2018, and it is going to be about 40 million tons in 2022. Considering these facts, copper welding is very important, and it is needed in almost all products manufactured in industries.
List of Contents
- Copper Alloys and TIG Welding
- Electrodes for Welding Copper
- RODs for welding copper
- Shielding Gas for welding Copper
- STEP BY STEP GUIDE TO TIG WELD-ON COPPER
- Frequently Asked Questions FAQ’S
Copper Alloys and TIG Welding
Copper is used in alloys in almost all the product. There are more than 400 different alloys of copper are available; however, only ten of these 400 alloys serve in 90% of the usages. These famous alloys of copper include:
- Copper-Nickel Alloys
- Nickel Silver alloys
You need to determine the right settings before start welding any of these allows. But don’t worry, this determination of configurations is not difficult.
Electrodes for Welding Copper
The right choice of an electrode is the most important part of a TIG welding procedure. We have narrow down the selection from hundreds of electrodes to just two. You can use these for AC and DC as needed. Following are the best electrodes for welding copper perfectly.
1. 2% Thoriated Red Tungsten Electrode
The main oxide used in this electrode is thorium oxide. This electrode is best if you are going to use DC for welding. The radioactive properties of this electrode should be kept in mind while using it. This thoriated electrode is also compatible with transformer-based power supplies. When working with corroding steels, you should choose this electrode.
2. 0.8% Zirconiated White Tungsten Electrode
This electrode has 0.7 to 0.9% zirconium oxide. Unlike our other choice, this electrode is non-radioactive and can be used for alternating current welding. This electrode can also be used for transformer-based constant current sources. You can also use it for higher current sources with better controls. This electrode offers less spattering and excellent for beginners in this field.
From my personal experience, these two are the best copper electrodes available. However, there is a wide variety of electrodes available, and you can choose any if that suits your job.
RODs for welding copper
Unlike other types of welding, TIG welding requires separate rods then electrodes. It would be best if you fed the rod continuously to the welding puddle. This creates rigidity in the welds. There are different options in the rods for TIG welding are available.
Among some best options are de-oxidized copper rods that can be used for high-end jobs. The outcome of using these rods is clean and attractive welds with strong strength. Beginners should not these rods as these are expensive and costs much at the start of the carrier.
On a professional scale or usually in industries, we need stronger welds. Thus, an even stronger filler metal is required. This level of potent can be achieved using silicon bronze rods. These elements are less expensive and show great results. They are also suitable for welding different metals together, so these must be your prime choice if you want to weld copper to iron or steel.
Most of the welding rods have texture and color shade which is different from the parent material. If you are more concerned about the aesthetic aspects of the weld as compared to its rigidity, then you can also use a 1/8” rod of parent metal. This creates a uniform texture and texture throughout the weld and welded metal.
For absolute beginners, there are other cheaper options available. You can use Romex stripped wires as these are cheaper and easier to find. They won’t give you that level of strongness and appearance, but these are a good choice at the beginning.
Shielding Gas for welding Copper
TIG welding uses a shielding gas to save the metals from oxidizing under the effects of high temperatures. Shielding gas can be pure or a mixture of different gases.
We use a mixture of 80% helium and 20% argon as a shielding gas for copper. These two gases support the working at higher temperatures, as copper requires very high heat for its welding.
Helium has a heat capacity that is 1.7 percent more than argon. You can also use pure argon if your pieces are thin or your welder is giant enough to cover the weld. However, it’s my advice that you should use helium along with argon in order to get the artistic welds.
STEP BY STEP GUIDE TO TIG WELD-ON COPPER
After gathering all the things mentioned above, you can start the copper welding job. Following are the steps you need to perform to weld copper.
1. Prepare the Workplace
Your workplace should be neat and clean before the start of your welding job. If you are welding in your shop, you should choose a place away from moisture and dust particles as these can contaminate your weld.
In TIG welding, you also need a lot of equipment to weld properly. Following are the main things you require when you want to perform TIG welding.
Bench Grinders are very necessary for preparing the electrode. Sharpening the electrode is very necessary for the precise performance of TIG welding.
These tools are needed for removing oxidations from the surface of welding material. For cleaning copper surfaces, the brush should be strong and fine-textured. The important thing you need to keep in mind is that you must not use the brush used for copper cleaning should not be used for any other job.
In order to clean the rust or paints from the surface of the workpiece. Acetone is a good choice for cleaning the grease from the surface of the metal. However, acetone is flammable, so in cases when you are more concerned about flames, you can choose citrus degreaser.
These are always necessary when you are going to perform any welding job. You will need a mask to protect your face against the sparks and harmful radiation of work. A welding jacket to save your clothes against the spatter of the weld. And you will also need to wear gloves for protection of your hands, as these are most near the fire. (Veterans in the war of welding!)
Preheating is one of the most important parts of TIG welding. As narrated above, you will need to preheat the copper to very high temperatures. For this purpose, you will require a propane torch.
2. Prepare the Electrode
According to the American Society of Welder, “An electrode which is sharpened well can increase the productivity to about 70%”. Your electrode should have a sharp pointed edge to achieve the precise welds.
To sharpen your electrode, you can use a bench grinder. You can also purchase a new electrode with a sharpening tip if you want the ultimate result. To whet an electrode, you need to take it away from the collet and run it in the grinder.
After the electrode has a well-sharpened tip, you can put it back in the collet and tighten it in its place. Better electrode grinders that can save time in sharpening can also be chosen.
3. Set up the Welder
After preparing your workspace and electrode, it is time to turn on the welder. Copper is a very good conductor of heat, and it requires very high temperatures to be weld properly. For thick pieces of copper, you will need as high a temperature of copper as 400 Amperes.
In the user manual of each welder, it is mentioned that at what temperatures it will be able to weld copper properly. I think it is a benefit of welding on copper that you can easily increase the amperages much high without destroying the workpieces. However, in the case of thin sheets of copper, you will need to choose your amperage ratings precisely.
As copper is a good conductor of electricity, you also need to ensure that the ground is perfectly in place. In welding copper, the chances of getting electric shock increase multiple times.
4. Prepare the surface of the Workpiece for Welding.
A worker should clean the copper’s surface from any contaminant before starting to apply the welding arcs. Acetone or any other solvents is a good choice for cleaning the surface of copper. Contaminants can destroy the aesthetic aspects of the weld to a great factor.
You can read my article on “Porosity in Welds” in order to check the main causes of contaminations in the weld and how to clear them. Citrus based greaser is also a good choice for surfaces that don’t have paint on them.
After cleaning the surface of your weld, you will need to put your solvent away from the welding place, probably in a cupboard, as these solvents are flammable and get fire quickly, even from a spark. So, they should not be anywhere near the surface of the weld.
5. Wear your protective instruments and make sure they are in the best condition
Copper releases fumes when welded. These fumes are very bad for your breath and can also damage the surface of your skin. You need to have good ventilation in the shop when welding copper.
Before starting the welding job, you should cover your whole body. If you don’t have good welding gloves and a welding jacket in your shop, you can read my articles on “Best Welding Gloves” and “Best Welding Jackets for TIG welding” to choose one for yourself.
6. Preheat the Copper Piece
Before start welding on copper, the worker will need to heat the alloy. For a copper sheet of 1 inch long, you will need to raise the temperature to about 60 degrees centigrade. However, this temperature increases with the size of copper alloy. A five-inch-thick sheet must be heated to 400 degrees centigrade before welding.
The preheat temperature also depends on the thickness (in other sense the density) of the copper alloy. However, it is wise to take a welder with you when welding copper that can release a welding current as high as 350 Amperes. So, the very important step before welding copper is to view the thickness of the alloy you will weld.
7. Start Welding Joint
After completing all these pre-requisites, you are ready to start your welding job. For this, you need to put both the separate pieces together and apply the welder to create the spatter.
It is the point here to consider that TIG welding is not an easy job. It requires both of your hands to be at work. It would help if you fed the filler metal from the other hand. It isn’t easy to perform but once done right; it can give you the best outcomes.
Frequently Asked Questions FAQ’S
What are the steps to TIG welding copper?
TIG welding on copper is not so difficult and is similar to any other kind of TIG welding. It requires high temperatures and more care as copper is a good conductor of heat and electricity. In TIG welding of copper, one needs to clear the surface of copper from any contaminant and preheat the workpiece using a propane torch. After that, you can start welding using a TIG welder. It is necessary to mention that you will need to continuously supply the filler material to the joint while welding.
What kind of Tig rods are used for TIG welding on Copper?
There are a number of different options available for TIG welding on copper. For the better appearance of the welds, you can use deoxidized copper rods which can give you strong and physically appealing welds. However, these rods are usually expensive for beginners to buy. So, in that cases, you can go for Romex stripped wires which are cheap enough and gives better results.
What is the difference between Stainless Steel Welding and copper welding?
Copper is a very good conductor of heat as compared to SS. So, welding of copper will require higher temperatures. You will need to set your welder at a high amperage rating. Also, copper welds get contaminated easily so before welding copper should be absolutely clean. The basic procedure of applying the welds is the same in both cases, but yes, in the case of copper, you will need extra protection accounting for the high electrical conductance of the copper.
In this article, I have covered all the important steps you need to perform to perform TIG welding on copper. I have also covered the electrodes you can choose and how to achieve good grinding applications. After reading this article, any beginner can perform perfect TIG welding on copper.