Copper vs. Non-Copper-Coated Welding Wire – 6 Benefits of Choosing Non-Copper-Coated Wire

Greater depth of fusion, cleaner welds, less spatter and reduced exposure risks to the welder – these are just some of the key advantages of non-copper-coated wire, which has become increasingly popular in recent years.

In this article, we take a closer look at copper-coated and non-copper-coated welding wire, their differences and advantages, to help you choose the right type of wire for your welding jobs.

This article includes:

• An introduction to the classification of welding wires.
• A discussion of the differences between copper-coated and non-copper-coated welding wire, including outer material, application and performance.
• An overview of the advantages and disadvantages of each type of welding wire, including weld quality, ease of use, cost, applications and health impacts for the welder.
• A summary and recommendations for choosing the right welding wire depending on the project.

Difference between copper-coated and non-copper-coated wire

MIG/MAG welding is one of the most important metal joining techniques used in many industries, including automotive, construction and metalworking. Different types of welding wire are used within this technique, including copper-coated and non-copper-coated wire.

Although both types of wire perform a similar function, there are important differences between them that many welders are completely unaware of due to the fact that they have never come to use welding wire that is not copper-coated.

First of all, these two types of wire differ in the material from which their outer surfaces are made.

Non-copper-coated welding wire has an outer surface made of pure weld metal (e.g. low-alloy steel, stainless steel or aluminium), while copper-coated welding wire has an outer surface coated with a thin layer of copper.

The copper coating is intended to increase welding efficiency by reducing the electrical resistance of the wire surface and improving heat dissipation. In practice, however, the copper coating causes several problems in the welding process, which we will discuss in later paragraphs.

In the case of non-copper-coated wire, it is coated with an antifriction, conductive coating with anti-corrosion properties, which is much thinner than copper, completely eliminating weld de-lamination and cracking. It also rules out all the problems associated with copper particle contamination of welding equipment.

Advantages of non-copper-coated wire

So what are the main advantages of non-copper-coated wire?

Greater penetration depth

Tests clearly show that non-copper-coated wire has a much greater depth of fusion, as can be seen in the attached image.

Cleaner welds and less chipping

Compared to traditional non-copper-coated, copper-free wire eliminates the process of copper electroplating on the surface of the material to be welded, which significantly reduces contamination of the weld.

Significantly less welding smoke – reduced health risk for the welder

When welding with copper-coated wire, smoke is produced due to the generation of copper fumes. When welding with non-copper-coated wire, blue or white smoke is produced, which means that this smoke does not contain the Cu element and is much less harmful to welders

In MIG/MAG welding, the smoke is primarily produced by oxidation of the metal vapour and copper is the main harmful element produced during the work. It should be noted that non-copper-coated wires are not completely free of copper content – however, the copper content in them is about 0.15%, which is marginal.

Statistics show that the amount of smoke produced from non-copper-coated wire is about 20 per cent lower than that from copper-coated wire. In short, this means that being in an environment where we weld with this type of welding wire is much less hazardous to the welder’s health – firstly because there is no inhalation of copper fumes, and secondly because there is much less smoke.

Improved arc stability and wire feeding performance

The special surface treatment process of non-copper-coated wire means that it does not shed the copper-coated layer, which means it can maintain a more stable wire feed for a long time, even in a high-speed condition, resulting in higher welding and deposition rates.

Longer life of welding equipment

With copper wire, copper passes through the wire feeder and weld holder, crumbling and clogging the wire guides. This causes the wire to wear faster.

With non-copper-coated wire, this problem does not occur – which in turn allows the welder to make significant savings on the current tips precisely.

Greater durability

It is a common misconception that a copper layer is more resistant to rust, as iron is more active than copper. However, the results of a corrosion test in a salt chamber where professional corrosion resistance tests are carried out (temperature 30℃, humidity 80%, stay in 0.01% NaCl solution for 2 hours) show that the corrosion of copper-coated wire is much greater than that of non-copper-coated wire.

The severe corrosion of copper-coated wire was found to be due to the rapid corrosion of the galvanic cells, which readily form where the fine copper layer cracks or flakes off.

In contrast, the surface of non-copper-coated wire does not come into contact with other metals and will not form galvanic cells, which means that its anti-rust ability is better than that of non-copper-coated wire.

Disadvantages of non-copper-coated wire

As with most technologies, non-copper-coated welding wire also has its drawbacks – let’s now turn to its two main disadvantages.

Higher cost

Improved welding quality comes at a higher cost. Non-copper-coated wire is significantly more expensive than its copper-coated counterpart. This is, of course, due to two factors – firstly, the chemical composition of the wire consists of much more expensive components

Fewer types of wire and lower availability

Secondly, most copper-plated wire is on a plastic basket, which also saves on price.

Non-copper-coated wire is found almost exclusively on metal baskets, which of course makes them much more resistant to breakage or other defects, but at the same time this increases the overall cost.

Copper-plated wire is available in significantly more variants than non-copper-coated wire.

In addition, non-copper-coated wire is still harder to find due to the fact that, despite its very good properties and better weld quality, many retailers still do not offer it.

Advantages of copper-coated wire

What are the advantages of copper-plated wire, which remains the most commonly used type?

Lower price

Copper-plated wire is considerably cheaper than non-copper-coated wire. This makes welders looking to save money on fast-wearing welding consumables more likely to opt for it.

Popularity

Copper-plated wire is much more popular than non-copper-coated wire. For this reason, many welders who have been accustomed to using this type of wire for years are reluctant to change to another type.

Multiple applications

Copper-plated welding wire is widely used in a variety of industries, including chemical, refining, automotive, industrial, and construction sectors.

Disadvantages of copper-coated wire

So let’s move on to the main copper-plated wire drawbacks.

Higher fume emissions – greater harm to the welder

As stated above, the higher amount of welding smoke and copper fumes that are produced during the welding process with copper-coated wire undoubtedly pose additional health risks to the welder.

Therefore, if you frequently weld in enclosed spaces with low ventilation levels, it is worth considering a permanent change to non-copper-coated wire – not only for the sake of better weld quality or strength, but above all for health reasons.

Much lower resistance during long-term storage

Copper welding wires are more susceptible to corrosion and mechanical damage, which makes it more difficult to store them long-term and maintain the same quality.

Less welding precision

Due to the larger diameter of the copper coating, copper-plated welding wires have lower welding precision compared to non-copper-coated wires.

Plastic spools with reduced resistance

Most copper wires are on plastic baskets, which means that they are much more susceptible to damage, breakage or even fracture.

Greater contamination of welding equipment

The copper that passes through the wire feeder and welding fixture crumbles, which causes clogging of the wire guide and faster wear of the current tips.

Bottom line – which wire to choose?

At the end of the day, we need to remember that choosing the right welding wire for the job depends on several factors, such as the type of material, material thickness, type of joint, welding technique and the mechanical strength requirements of the weld.

However, if we often weld materials such as unalloyed steels, low-alloy carbon-manganese steels and structural steels – it is definitely worth trying a non-copper-coated wire, not only for higher productivity, better welds, but above all for health reasons.