You can weld copper using a TIG welder, but it’s not as simple as you think because of the rare peculiarities of this metal. As we know, copper is the finest heat conductive metal on the planet after silver. That’s why, when you start the welding process by providing heat, it will heat up instantly, so be ready to tackle the heat.
Moreover, it isn’t wise to weld copper without wearing protective equipment because spatters of molten copper are genuinely inimical. However, the most important thing is to execute the job quickly because the molten copper shortly bounces back to its solid-state.
Welding copper through a TIG welder is not as tough as we generally assume, but some technicalities demand utter attention. Most people make the mistake of welding copper as steel and end up maligning their project. If you are there to learn how to TIG weld copper, then keep up reading.
Get the right copper for your work
Picking up the suitable copper is the first step towards TIG welding copper. It is suggested to buy copper without any oxygen content. We are telling this because some grades of copper have oxygen in them. If a copper has oxygen, then the weld bead will contaminate during TIG welding. Pure copper (oxygen-free forms) grades are now readily available in the market as their application in the electrical field is inevitable.
Some highly proposed copper grades for your welding work are as follows:
The copper content in this grade is about 99.90 percent. It’s also known as electrolytic tough pitch copper.
The amount of copper in this class of copper is nearly 99.95 percent. It is also recognized as oxygen-free copper.
The percentage of copper in this category of copper is approximately 99.99 percent. It’s also regarded as oxygen-free electrolytic copper.
Among these three oxygen-less copper grades, C11000 is cheap, so you can easily afford it for a welding project. Moreover, higher copper volume grades than C11000 are employed in welding when an engineer approves them for the project. Besides, never use scrap copper because it has a huge percentage of oxides, and the weld you produce will have bubbles.
If you are looking at copper for brazing and soldering, scrap copper is not bad, but it is not good for welding. Additionally, if you’re welding for storing water, then we advise you not to use copper in the form of alloy. The reason is metals in the alloy other than copper are none edible and get dissolved in water, and are harmful to health.
Now pick other necessary materials
After you have got the reasonable copper as a base metal, it is time to gather other materials you need to start copper welding. These are
The electrode is the component of a welding machine from which shielding gas passes. Also, the electrode generates an arc, which melts the base metals to create joints. And the electrode you use will determine the quality of welds you produce. That’s why it is necessary to choose the correct electrode.
Some important electrodes we suggest you are:
- Serrated tungsten
- Rare earth mix
- Thoriated tungsten
- 2 percent lanthanide tungsten
- 5 percent lanthanide tungsten
You can buy any one of them as all of these electrodes are suitable for welding copper. However, these electrodes have their differences like arc stability, and specialty for AC or DC welding. Moreover, you can try all of them to realize which one is ideal for you.
Do you know in TIG welding, there is a different role of electrode and rod, unlike other welding techniques because the electrode isn’t consumable in TIG welding? While TIG welding copper, you need to hold the electrode in one hand and the rod in the second hand to create weld beads.
From the market, you can easily buy oxygen-free TIG rods. These are made especially for TIG copper welding. Mainly, you can get clean and smooth welds with the utilization of these pure copper rods. Besides, the color of the welds and the base metal will be similar, which is worth mentioning. Therefore, with all these qualities, these rods aren’t cheap at all.
Other than oxygen-less rods, you can purchase silicon and bronze alloy rods for your project if you want strength and durability. Moreover, they are more vigorous than any other rods you can get for a TIG welder to word copper. In addition to this, these rods are excellent if you have to weld copper with steel or iron.
The color of the welds and metal workpieces will not be identical, which is why the price of these rods is affordable. If you are going to practice copper welding with a TIG welder, then you can also use Romex wire, which is much cheaper than every welding rod available.
As we know, a TIG welder generates extreme heat, which tends to oxidize the weld and make it brittle. To avoid it, the TIG welding machine continuously throws shielding gas which protects the weld from contamination. Moreover, there are various types of shielding gas composition to execute the task.
We suggest using 100 percent helium or 80 percent helium and 20 percent argon mixture to shield gas. You may be thinking about why we prefer helium and helium-argon mixture over pure argon. The reason is the use of helium over argon boosts arc temperature by 170 percent.
The copper requires a lot of heat to get into a molten form. That’s why helium is ideal for this job. Also, if you have a TIG which has low amperage and you have to weld thick copper, then productivity will get better with helium. But you can take argon as a shielding gas if you’re welding thin copper.
Other materials you need
You can prepare electrodes with a bench grinder before the start of welding.
The purpose of cleaning solvent is to pre-remove the tarnish, paints, and other impurities from the weld.
To clear oxides from the weld, you need to acquire the wire brush, and it’s must to have if you want seamless and clear joints
For protecting yourself from spatter and blindness from the arc, you need to have gloves, a helmet, a welder jacket, heavy jeans, and special boots.
Prepare the welder
To weld copper, you need to put a lot of heat on it. That’s why a heavy welder with high amperage is required. If you have to weld dense copper pieces altogether, then you have no choice but to get a high amps TIG welder. Mostly expert welders set amperage at 300 to 400 for thick copper welding.
Always join the return clamp to the base metal form welder. Ensure the grounding because you can get the shock if something about wiring goes wrong because of the excellent conductivity of copper. In addition to this, avoid touching copper without wearing gloves to protect yourself from electric shocks.
Use solvent and brush to shine copper
Now, after you have set up your TIG welding machine, it’s time to clear oxides from the copper with the use of a wire brush. While scrapping with a wire brush, make sure that no oxides are left on the copper to avoid bubbles in welds. In this way, you will produce stable and smoother joints.
Besides, the oxides you have to clean dirt, paints, and any impurities of copper have with the use of solvent. The solvent can be acetylene or any solution with citrus acid due to the excellent cleaning nature of citrus acid. Additionally, you can also go for a degreaser if you don’t less smell of acetylene.
Wear protective equipment
A wedding isn’t a safe job; if you can’t wear protective measures, you will end up hurting yourself. There are many cases in which welders burn themselves and even lose their eyesight by skipping protective measures. First of all, cover your hands with leather gloves, which save you from molten copper spatter and electric current.
After that, wearing a helmet protects your head and eyes as welders usually have to accomplish the task on construction sites. Moreover, wearing a welding jacket and jeans protects your remaining body from the spark of the head and spatter. If you are welding over the head, then there are great chances you will burn your feet with spatter if you can’t wear special welding boots.
Now perform welding
After strictly following all the things we have told before, you are now ready for TIG copper welding. Due to the heat sink property of copper, you have to first preheat the whole copper metal. To avoid install cooling of entire metal preheats it at 300 to 700 degrees Celsius.
Now arrange the metal at the appropriate angle to weld and put in a rod where you need to weld and strike an arc over it. When you see a puddle is there, use the rod to spread it and keep on the striking arc at a constant pace to create a full and smooth joint.
Further, you need to look after thin copper more because the excessive heat will completely tear it, which is not good for your task. We suggest you apply soldering or brazing than TIG welding for extremely thin metals.