How To TIG Weld Copper? Complete Guide with Technique

How To TIG Weld Copper? everything we wrote about that.

One of the oldest metals still in use today is copper, which has left its mark on human history. However, because of its advantageous traits, it is still helpful today.

Many welders are unfamiliar with the procedure when they are given a job that requires them to weld copper pipes or other components.

Due to its special characteristics, which might result in cracking, deformation, or wrapping, welding copper isn’t the easiest process. In this article, we’ll give you some tips on how to successfully TIG weld copper and discuss how the TIG welding technique may be quite helpful in managing heat.

Characteristics and Importance of Copper

A soft, pliable metal with good electrical and thermal heat is copper. It is one of the most common elements on Earth and is present in traces in rocks, soil, and ores. For thousands of years, copper has been utilized in a wide range of products, including jewelry, coinage, and buildings.

Today, copper is utilized in many different applications, such as plumbing and electrical wiring. Along with being used to create structures and monuments, it is also utilized to make coins and jewelry.

Copper is also utilized in the automotive industry for heat sinks for electronic components, radiators, and heat exchangers. Copper is utilized in the medical sector for surgical instruments as well as medical implants like pacemakers. These contain particular grades, but you should get oxygen-free copper for normal household welding and uses.

How to TIG Weld Copper? Why is Copper Difficult to Weld?

Because it has a number of characteristics that can affect weldability, copper is a highly difficult material to weld. Due to its considerable malleability and ability to be easily deformed without breaking, pure copper is a ductile metal. This might cause the material to twist and distort while being welded, which makes it harder to get a neat, even weld.

Another problem is that copper easily and quickly transfers heat due to its high thermal conductivity. This may result in an incomplete fusion and poor weld quality by causing the weld junction to cool more quickly than anticipated.

Additionally, because copper has a low melting point, welding may result in it burning too quickly and getting excessively hot. Due to the heat’s unpredictable nature, this can be particularly problematic when trying to weld thin or small bits of copper.

Is TIG Welding a Reliable Method for Welding Copper?

The primary benefit of TIG welding copper is the production of high-quality welds, which is made possible by careful management of the weld parameters. This comprises the amount of heat input, the welding process’s speed, and the size and form of the weld pool. TIG welding is also particularly adaptable because it can be used on a wide range of metals and alloys, such as copper, copper pipes, and copper fittings.

TIG welding is excellent for combining thin pieces of copper or mending sensitive goods since it can be used on thin materials. TIG welding does, however, have some disadvantages. Compared to other welding techniques, it takes longer and requires more expertise. It also does not yield a high weld deposition rate, making it potentially unsuitable for applications requiring extensive welding.

How To TIG Weld Copper?

TIG weld Copper – In brief, there are a few essential parts needed to TIG weld copper. First, you need a TIG welder that is appropriate for the task. Because copper has different thermal properties than steel, the ideal TIG welding machine for copper needs to have a greater welding current.

Additionally, you will require a tungsten electrode, which is typically constructed from either pure or thoriated tungsten. The thickness of the copper being welded and the welding machine’s current will determine the size and kind of tungsten electrode.

Additionally, 100% straight polarity Helium is the preferred option for shielding gas, however welders also use Ar/He combinations. It will assist in achieving the necessary heat and penetration on copper tubing or copper pipe as well as protecting the weld from contaminants.

To avoid contamination when using the TIG welding technique, you should maintain your filler rod inside the shielding gas. Once the weld pool is established, you should move quickly with high amps (about 200A) and exit the weld as quickly as you can to avoid heat buildup and metal melting.

Finally, depending on the application, you will require a filler material, which could be a clean copper alloy rod. Even though it can seem difficult, you can complete it by following our step-by-step instructions.

TIG Welder Copper

You will require a TIG welder with a Constant Current (CC) power source, a foot pedal, or a fingertip control in order to TIG weld copper.

The thickness of the material will determine the amount of amperage needed to TIG weld copper. TIG welders for hobbyists typically range in amp rating from 25 to 250. However, compared to steel of the same thickness, copper will need 30 to 50 amps more due to its thermal qualities.

Direct current electrode negative should be selected as the polarity for TIG welding copper (DCEN). This implies that the workpiece (copper) will be linked to the positive side of the power source and the electrode (tungsten) to the negative side. In this manner, you attain adequate heat and penetration.

A few unique characteristics exist that may be useful. For instance, using a pulse function when welding thin gauge materials can be beneficial because it can lower heat input and enhance weld quality. A post-flow feature may also be helpful for preventing oxidation of the weld puddle. Last but not least, balance control is useful for welding copper because it enables the operator to regulate the proportion of cleaning action to penetration.

Choosing the Right Tungsten for Copper Welding: TIG Copper Welding

Thoriated tungsten electrodes are the ideal tungsten electrodes for TIG welding copper. Thoriated tungsten is a kind of tungsten that has a minor quantity of thorium oxide added to the alloy (ThO2). The electrical conductivity of the tungsten is improved by this addition, which is crucial when welding copper.

Thoriated tungsten is more resistant to wear during the welding process since it also has a greater melting point than pure tungsten. This is crucial when welding copper since the metal has a rather high melting point and can quickly lead to the tungsten electrode degrading. Thoriated tungsten electrodes are the best option for welding copper because they have a lower rate of contamination than other tungsten electrodes. A pointed electrode is the finest for welding copper (sharp point).

TIG Filler Rods for Copper

Silicon-bronze rods are the ideal filler rod type to use for TIG welding copper. The strength and weldability of silicon-bronze alloys are well recognized. They are perfect for welding copper since they have a low melting point. They have superior electrical conductivity and excellent corrosion resistance. They are also reasonably priced, which makes them a practical option for welding copper.

Silicon-bronze alloys provide greater strength and weldability as compared to other filler rod types, such as aluminum-bronze or deoxidized-TIG rods. They also have a lower melting point than other filler rods, which makes welding faster and simpler.

They also offer exceptional corrosion resistance, which is crucial for welding copper. Additionally, when welded copper has a purity of over 98%, bare copper wire filler ERCu may be employed. Solid copper electrical wire is an option that, in some circumstances, can produce satisfactory results.

Choosing a Shielding Gas

Inert gases that don’t interact and contaminate the tungsten or weld pool are necessary for the TIG welding process. Helium and argon are often used TIG gases. When using TIG welding for thicknesses under 1/8 inch, pure argon is the preferred welding gas. However, argon doesn’t have much heat, which is important when countering copper’s characteristics.

Copper weld with 100% Helium

All copper alloys are excellent heat-absorbers, 4 times better than mild steel. You receive that extra heat transfer when welding copper with 100% helium, which makes this a considerably faster welding procedure with greater penetration and at higher amps than typical.

You can effectively weld thick copper using 100% helium, but there are certain disadvantages.

Pure helium is expensive, doesn’t provide the best arc stability, and can produce spatter due to its greater temperature. In addition, it frequently gets excessively hot nearby, so you should take extra precautions.

Copper weld with 80% Helium Shielding, 20% Argon

The optimal shielding gas combination for TIG welding copper is frequently thought to be 80% helium and 20% argon, particularly when the thickness of the weld metal exceeds 1/8 of an inch. Helium works well with copper or other thick metals because it offers tremendous heat and penetration. However, when TIG welding copper, welders typically employ a helium/argon mixture since argon is less expensive and helps to stabilize the arc.

Different copper alloys still call for a helium-rich mixture, which is more expensive but produces better results, as opposed to 75/25 Ar/He for steel. Welders have varying ideas and preferences, and some even prefer using 100% argon on thinner pieces of copper sheet.

Prepare for weld

For TIG welding copper, weld preparation is a crucial phase that shouldn’t be skipped. Before welding, it is advisable to clean the copper’s surface to get rid of any potential grit, dust, and grease. To accomplish this, any traces of foreign material should be removed using a wire brush or grinding wheel.

It is crucial to thoroughly dress the edges of the region that will be welded. This is accomplished by polishing the edges to make sure they are flush and won’t obstruct the welding procedure. The weld will be as robust as possible and won’t have any weak spots from inadequate preparation thanks to this phase.

Preheating the Copper

Depending on the thickness of the material, the ideal preheating temperature for TIG welding copper is between 50 and 750 °F. Due to copper’s strong thermal conductivity, preheating is necessary, but the temperature shouldn’t be raised above the maximum advised level of 800 °F.

The segments of the metal parts that need to be bonded initially need to be uniformly warmed. This lessens the likelihood of cracking by allowing the heat to disperse gradually.

High temperatures will also make it easier for you to keep the arc stable and ensure appropriate penetration all the way through the weld. The copper will absorb heat if the pieces cool down instead of melting at the necessary temperature to fuse with the other parts and filler rod.

Welding Safety in Copper Welding Procedures

Because of the thermal characteristics of copper, preheating the base metal and using only 100% helium might result in a significant buildup of heat. Additionally, copper has a high conductivity, which allows for rapid electrical current transfer. Contact with the arc or too much heat can therefore result in severe burns or electric shock.

Wearing appropriate personal protection equipment (PPE), such as welding helmet, gloves, and flame-resistant clothing, is advised at all times. As sparks from welding could ignite combustible objects, it’s also crucial to make sure the workspace is clear of them. Make sure you weld in a well-ventilated area or use a respirator if there is no local or general exhaust system since the alloys in copper, like zinc, can produce deadly copper vapors.

Additionally, be sure the power supply you are using is appropriate for the task at hand. If the power supply is insufficient for the amount of amperage needed for welding copper, both the operator and the power source may be damaged.

Copper Welding Technique

Consistency is essential for good welding of any metal, even copper. Maintain a modest arc length and feed the rod steadily. Remember though, copper cools down quickly. You shouldn’t move too slowly as a result.

The arc will be put out if you go too slowly, but you can prevent this by turning up the heat with your foot pedal or torch control. Of sure, provided that you don’t puncture it.

Aim not to burn through copper sheet when TIG welding. You can easily burn through copper because it needs a lot of heat, so use caution. Although the pulse feature can be used to work with thin metals, typical TIG welding is done at DCEN polarity because it offers superior heat input and penetration.

Options Besides TIG Copper Welding

Other methods besides welding can be used to join copper, such as:

Oxy-Acetylene Welding: Oxy-acetylene welding is a popular substitute for TIG welding copper because it creates a strong bond with little heat input. This kind of welding uses a welding torch tip to ignite a mixture of oxygen and acetylene gases. As a result, a burning flame that is so hot it can heat metal is produced. The temperature of this flame can range from 2,600 to 3,000 degrees Fahrenheit depending on the type of copper being welded (1427-1649 Celsius). Thin gauge metals or big cast components can be joined using this welding technique, which is less expensive than TIG welding.

Soldering: Using heat and filler metal to join two pieces of metal together, soldering is another option to TIG welding copper. This kind of welding is frequently used for thinner gauge materials because it doesn’t require high temperatures like other kinds of welding. The most popular solder for copper is a tin and lead alloy, while there are various lead-free alloys available. Soldering has the benefit over TIG welding in that it is more time- and energy-efficient and cost-efficient.

Brazing: TIG welding copper can also be done using brazing, which is a process that uses heat and a brazing rod to join two pieces of metal together. Brazing is similar to soldering. Temperatures needed for this sort of welding are typically between 1,400 and 2,000 degrees Fahrenheit, which is greater than those needed for soldering (760-1093 Celsius). Brazing can be utilized in circumstances when strength and aesthetics are not as important as they are when TIG welding copper, even if it may not be as robust. Additionally, due to its relatively inexpensive tools and materials, brazing is typically more economical than other types of welding.

FAQs

Conclusion

Now conclude, TIG welding copper can be challenging, but recognizing the problems and difficulties is the first step to creating a good weld. You are prepared for success once you have a handle on the welding settings, preparation, filler material, and tungsten selection.

For your copper project, weld preparation is just as important as the welding procedure itself, so don’t be afraid to take your time and weigh your options.

Finally, you shouldn’t have too many problems with TIG welding copper if you follow our thorough tutorial, practice, and patience.