Mig Welding Wire

With so many different brands of mig welding wire on the market these days, It becomes hard to make the right selection of a quality mig welding wire.

Mig welding wire is just wire....isn't it? There all the same?

Well in actual fact there are many things that separate one brand of mig wire from another.

Things like;

• Raw materials used
• Copper coatings
• Wire diameter tolerance
• Wire cast
• Wire helix
• Wire consistency

These are all things that need to be looked at, in order to make the correct decision on which wire to run with.

What's more is:
.

• Does the wire need to be of any standard?
• Does the wire need any approvals?
• Does your engineering department need a copy of the welding consumable certificate?
• Does your engineering department need a copy of the mill certificate?

So having just mentioned all this, can you start to see that wire isn't just wire?

And that there are many things that determine the quality of welding wire?

Okay, so what do you mean by all of this?

---

Raw materials used

The quality of mig welding wire starts from the very beginning in the manufacturing process. What are the raw materials that the wire manufacturers are using? Are they using new raw materials or are they using scrap steel?

Some welding wires will actually be made from recycled scrap steel, i.e. old ships and cars are cut up and melted down. Then when the scrap metal is refined not all of the impurities are removed. This leaves you with a wire of a much lower quality, which in turn results in a whole range of issues such as, spatter, burn backs, porosity and feed issues.

This is why you need to ask for a mill certificate. This will show the quality of the raw material that is used straight from the start of the wire manufacturing process.

---

Copper coatings

The copper coating is the copper coating which is on the outside of the mig welding wire. It is there to serve a variety of functions, not just to look pretty.

Why is it important to have a copper coating?

. Copper is an excellent conductor of electricity. It provides good current pickup at the contact tip during welding.

. As copper is softer than the wire itself. The copper coating acts as a soft abrasive action whilst travelling through the contact tip, as opposed to having the harder wire wear the contact tip out.

. The copper coating also serves as a protective layer. If there was no copper coating on the wire, corrosion of the wire surface would eventuate much quicker, rendering it unusable.

What type of testing of copper coatings does your wire manufacturer perform to ensure consistent even copper coating on their welding wires?

For example, look at these pictures below of a .Copper Adhesion Test..

Notice that this is zoomed in with 500 times magnification. It shows acceptable and not acceptable copper coatings.

Does the manufacturer of your MIG welding wire regularly perform these quality assurance tests?

---

Wire diameter tolerance

What size wire do you run? 0.9mm, 1.0mm, 1.2mm?

There.s not much difference between wire sizes. I mean come on what.s 0.1mm between wires? That.s like nothing!

What are the tolerances on the wire that you use? What are the manufacturing tolerances? +- 0.1mm?Is the wire just oversize, under size or both? And what effect does this have?

Wire feedability is critical in welding. You don't want the wire to stop start, stop start, shudder in the liner, slip at the rollers, burn back and so on. One area to look at is the manufactures wire diameter tolerance and the wire consistency. You want a wire that has the tightest possible tolerance and the best consistency.

Now using the same diagram, I'll put in the feed rollers.

Now as you can see. The good wire with the tighter tolerance and the best consistency is always in contact with the feed rollers. There is no possible way of the wire slipping in the feed rollers, as maximum contact is achieved with every revolution of the feed rollers.

But on bad wire you can clearly see the difference.

The wire diameter is all over the place, oversized undersized and is not consistent. What this means the feed rollers at one point will slip because the wire is under size.

Then when the wire is oversize the wire will bind up into the feed rollers. This binding in the feed rollers will add more pressure to the wire, which will cause the copper coating to flake and come off. The bits of copper will then in turn go down the liner of the welding torch and cause even more problems.

So you can see why the wire tolerance and consistency is absolutely critical for reliability, less down time and less frequent replacement of consumables.

---

Wire cast and helix

Mig Welding Wire Cast

Arr, what are you talking about!

Wire cast and helix is how the wire unwinds and unspools. This has an effect on weld accuracy, arc wander, consumable life and contact current pickup.

The cast of the wire is how large a diameter of a circle it would make if you were to cut a length off the spool. Is it going to have a diameter of 1ft or 4ft or 10ft? See diagram below.

Mig Welding Wire Helix

The helix of the wire is like a spring. It.s how far away the bottom wire is to the top wire in one revolution. If you were to unwind some wire and place it on a flat surface, it is how much it springs up. See diagram below.

Okay, so now you know what wire cast and helix are.

What effect does this have?

The majority of welding torches on the market today all pickup the current and transfer it to the welding wire via the contact tip.

Thus the name for a "contact tip".

If the wire cast is too small the wire will make a tighter bend as it exits the gun. This tighter bend in the wire will feed through the contact tip with more pressure, which will lead to premature contact tip wear. See diagram below.

If the cast is too large it will also have a negative effect. The wire will tend to be .loose. in the bore of the contact tip and not have a good contact for the current to flow.

With wire helix, if the helix of the wire is all over the place and not consistent. The wire feeding out of the torch will always be changing its position.

So if you are welding with a robot for example. Ideally you want to keep the wire tracking along the weld gap or area to be welded in, within about one wire width.

This is a very small tolerance to adjust for, especially if it is on a robot.

Imagine if you are making a weld 1meter long. If the wire comes out .on target. all the time, the weld will be successful. But what if that wire changes direction all the time?

Left then right etc.

Yeah sure it is only a small issue, but these are some of the things you need to be aware of when purchasing a quality precision welding wire.

---

Wire consistency

Wire consistency is also a very crucial and critical issue to consider when making an informed choice about welding wires. I have seen and heard of many people in the welding industry, be it either the smaller box trailer manufacturer, who has two welding machines and only uses two spools of wire a month right up to larger companies who might have 50 welders or more.

They have all had issues with mig welding wire consistency. For example, the first ten spools are great and the welding is fine etc. But then they go to put on the next spool and it.s rubbish. Consistency is a big issue. You want a welding wire that you can rely on, day after day, year after year, spool after spool.

If that spool of wire causes you or your workers to have to stop welding and find out what's going on. It is going to cost you time and money. If it is a business you run, you want to make money not lose it to downtime.

If you are looking for one of the world's best solid MIG precision welding wires, you can't go past

Kiswel KC-28 mig welding wire.

Consistently time after time, spool after spool it never lets people down. Precision layer wound, copper coated, ER70S-6.