Do you want to be a better MIG welder? Just as athletes need methods to increase performance, so welders have different techniques to improve their welds. The more you learn about these techniques and perfect each one through practice, the better a welder you will be.
There are numerous different techniques that we will walk through under the categories of travel speed, torch angle, and welding patterns. Then there are five MIG welding procedures: flat welds, horizontal welds, vertical down, vertical up, and overhead welding. We will look at these and learn the different techniques needed for each one. Following the tips for these techniques will turn your welding from average to amazing.
Briefing to Techniques
While theoretically, using the right techniques will absolutely transform your welding, realistically, what works for one person doesn’t always work for another because people do things differently. When you use welding robots, on the other hand, the consistency of their welds means you can apply a welding technique for them to use, and they should produce the same results every time.
This means learning the different techniques is crucial to your performance, but the way you may do them can differ from the way someone else does, and therefore shouldn’t override what brings you the best results.
If something isn’t working, there is no harm in changing the technique. What matters most is the end product. However, learning these techniques will bring you results. Just be open to your own experimentation with them.
This is the speed at which you move the weld pool along. The material you’re welding will determine how crucial it is for your speed to increase. All materials will warp with excessive heat, and the longer you’re welding in the same spot, the hotter your job will get. Therefore, the faster you weld while ensuring sufficient penetration, the better.
A big part of welding is the time factor. A precise, deep, and great-looking weld is crucial, but you don’t want to spend all day on five welds. There are ways to travel faster and still produce the same results. For example, you may have the welder on a particular setting that enables you to move five inches per minute. If your welder settings are on the lower side, you can increase your settings to run it seven or eight inches per minute while still producing an accurate weld with good penetration.
Always make sure your welds are not compromised by the increase in speed, but there is generally a healthy margin between too low and too high amperage.
Your torch angle is the position you hold the welding gun at while laying a bead. It can be at any angle in any direction and is always determined from the starting point of 0°, which is when your torch is perpendicular to the material you’re welding. That is perfectly 90° from the base metal.
For butt welds, your welding angle is any degree from 0° to 90° in any direction 360° around the axis of your torch. Fillet welds, on the other hand, have two sets of angles. The first is the angle your torch is pointing into at the corner of the joint. 45° is exactly halfway between the horizontal and vertical faces you’re shooting into. The other angle is your traveling angle facing towards or away from the direction you’re welding, having 0° as the center point.
A. Butt Welds
Sometimes the position of the weld on your project will give you only a few options, depending on how difficult the joint is to reach. For the most part, however, there is quite a choice. Learning the differences will change your weld profile from an ugly weld to a much nicer one.
Anything 15° or more past the 0° position is too much angle if you can help it. Welding roughly between 0° — 15° pushing or pulling (facing towards or away from your travel direction) is the ideal range to choose from.
Ideally, you want to keep the torch as near 0° as you can. Up to 15° will still produce pretty welds, but when your project requires a steep angle, don’t shy away from it. The reality of your weld location always rules the ideal angle.
The more angle you give to your weld when pushing, the flatter and broader your weld profile will be with less penetration. The more travel angle you use when pulling your weld along, the narrower and deeper your weld will be, but a taller, more prominent bead will result.
B. Fillet Welds
The ideal angle to weld into the fillet joint is 45°. Generally, you will be weaving up and down from the base plate to the top plate continually, so the angle will be changing. You want to keep the 45° point central, otherwise you will have uneven penetration and a weak joint.
For the travel angle, again somewhere between 0° — 15° pushing or pulling will produce a nice weld. Sloping any more degrees, either way, will start creating the same results as described for the butt weld.
Welding patterns are the different ways you weave a weld through your joint to spread out the weld profile and add or subtract heat from the bead in certain places. Each pattern produces a slightly different-looking profile and is especially useful for achieving the more difficult welding procedures.
People try weaving every pattern imaginable, and it would take a list many pages long to include them all. These are the five base patterns, and modifications to any of them are possible if you want more emphasis on a specific part of the pattern stressed.
The circular pattern weaves a continual set of oval patterns through the joint. It provides even coverage and good penetration, as the bottom of the circular pattern brings the heat and filler wire back into the weld so there are no cold spots in your joint.
This is an all-around beneficial welding pattern to give a tidy-looking weld with even heat transfer across your joint in any position.
2. Convex C
This pattern is similar to the circular weave, except the torch stops halfway through the circle, making a C, and cuts across the weld to form another C just in front. The tips of the C motion pause between the change of direction, providing deeper penetration and extra “meat” to the toes of the weld (weld edges).
This is useful for overhead positions, as well as the flat butt position where there isn’t too big a gap to fill.
3. Concave C
This pattern produces results between a circular weave and a convex C pattern. It adds a little more weld build-up to the center of your joint than the convex C does, due to the torch bringing the heat and wire back into the center of the bead. It also keeps the edges of the weld full, due to the pause between transitions that adds good edge penetration.
The concave C is useful for both vertical up or down welding and fills large gaps effectively when you don’t want the weld to blow through the center. It provides good fill over the whole joint, while setting some pre-weld on the edges of the gap to help bridge it before too much heat reaches the center.
The triangle pattern is very similar to the circular motion but has a slight bit more emphasis on the three points of a triangle than the fluid, circular weave. The two bottom points are where you stop to the left and right of the joint, and the one top point of the triangle is where you stop at the middle of the joint.
This is a particularly useful weave when welding vertical up welds, to stop the weld pool from running downwards when it needs to travel upwards.
The zig-zag pattern spreads out the weave but doesn’t provide as much penetration. It is useful for covering over welds when doing multiple passes, or for keeping excessive heat out of your project when welding.
What Techniques Are Used for Each MIG Procedure?
Out of the different MIG procedures, the flat welding procedure is the easiest, but sometimes your project can’t be positioned in a way that provides level welding options. Because this is the case, it’s necessary to learn all five procedures and the different ways to weld them.
Flat welding is where your job sits roughly level, so there is no incline at the point you’re fusing the metal. This is the best procedure to weld in as you generally have a comfortable position over the weld. Gravity keeps your pool in place to move where you want it to naturally, and it provides deep penetration without much heat.
For welding techniques, you can either push or pull the weld, both of which can produce beautiful welds. Each method has its own benefits, but there is a minimal difference if your welding angle remains within 15° either way. It’s mainly personal preference that determines the way you want to weld it, but sometimes the location of your joint makes one method a better option than another, and so it’s helpful to gain skills in both.
Pushing prevents weld cracking slightly more effectively by preheating the section you’re welding into. This is where the joint ahead of your weld is heated up, so when your weld reaches it, there is not a sudden change of temperature from cold to hot. The push weld will have a wider bead and slightly less penetration as a result.
Pulling produces a little more penetration than pushing, but it can be harder to see where you’re going. It provides less preheating to the rest of your project due to the arc facing the opposite direction from the unwelded space. The bead is narrower and more raised than pushing the weld.
A horizontal weld is where the section you’re welding is level from the start to the finish of your weld, but vertical from the top to the bottom of your weld. It’s more difficult than a flat weld, but not quite as challenging as a vertical or overhead weld.
The weld pool wants to run down from gravity onto the bottom section you’re welding, which, unless compensated for, gives uneven penetration between the joint. Welding with your nozzle underneath the weld with slightly lower amperage ensures an even weld distribution and a nicer-looking weld.
Weaving the torch slowly up and down in a zig-zag pattern between the joint, with a little more emphasis on the top section, will keep the weld evenly distributed between both parts. Pushing the weld along will also allow it to cool fast, preventing it from running.
3. Vertical Down
The vertical down procedure is where the section you’re welding is in a vertical position, and you’re welding down the slope, not upwards. Typically it’s at a 90° angle off level, but it can be roughly any angle between 15° to 90°.
It’s a harder position to weld in. The pool wants to run downhill and can quickly leave a big ugly blob if you don’t keep up with the weld, or use the right techniques. This downward weld is only used if the weld is not critical, as the penetration is always less than vertical up welding.
The key is to travel fast enough to keep the weld consistent without blobbing, but not so fast that you skimp on weld volume. Zig-zagging or circling down with your torch facing upwards helps to slow down the process and gives better penetration and weld distribution. It also fills your nozzle with junk, so make sure to clean it out regularly.
4. Vertical Up
This type of weld, along with the overhead position, is the most difficult. When faced with vertical welds, it’s necessary to travel upwards on most occasions except pre-welds, or non-critical welds. As you move upwards, the weld wants to drip downwards because of gravity, which is why it’s difficult. However, completing the weld properly can look really nice and never lacks deep penetration.
The technique to vertical up welding is to run triangle-shaped patterns all the way up the joint, with lower amps than you would generally run for other procedures. The torch should be angled towards the top of your project with the push technique, and the triangle motions are fluid, so it will feel like you’re welding out-of-shape circles.
This pattern will gradually bring the weld pool up to the top and provide an immensely strong weld from the deep penetration that occurs. It also can look really nice, although the center of your beat is typically more raised than the toes of your weld.
The overhead welding position is similar to the vertical procedure in difficulty because they are both fighting against gravity. It can be challenging to master, but with the right technique and a little practice, you can achieve a smooth, strong overhead weld.
It is usually necessary to weld this procedure with several passes. Two can suffice, but generally three is best, as it will produce the strongest and nicest-looking weld. If the gauge you’re welding is not very thick, three passes may warp your job. Consider your plate thickness before choosing how many welds you want to run.
When you weld each pass, treat it like a horizontal weld by weaving or swirling circles through the joint. If you’re running two passes, keep the bead narrower for the first pass. Then, weave a wide weld to cover the first bead while feeding more wire into the outside edges rather than the middle, so it creates a uniform finish.
When you weld three passes, follow the same principle. For the second two welds, you want to focus on one side each. For example, the first pass will be in the middle of the joint, and the second pass will fill the left side of the joint up to halfway through the weld. The third pass will fill the right side of the joint up to halfway through the first weld, meeting the edge of the second pass.
MIG welding is by far the easiest kind of process to weld, due to the automatic feed and how simple it is to strike an arc. This makes perfecting these techniques an easy process, as there is much less to think about and learn as opposed to stick and TIG welding.
Learning these techniques will definitely improve your welding, but feel free to use your initiative to adapt the methods for your welding style or the specific details surrounding your project.