It’s not very widely known but welding is very complicated that requires knowledge of hundreds of variables for someone to effectively master it.
However, as a beginner, don’t let this overwhelm or discourage you from learning. Most of the technical knowledge required is theoretical that can be mastered once you have an idea about them.
One of these things is welding techniques, particularly, two of them – push and pull welding. Both are very popular welding techniques that result in different types of welds.
In this guide, we’ll take a look at both of these techniques in-depth, understand the differences, and explore what makes one better than the other.
One of the most common methods of welding is the MIG (Metal inert gas) welding method also known as ‘wire welding’. In this type of welding, the base metals are joined with the help of filler metals that come out of the welding gun alongside the shielding gas (which is generally a mixture of 75 percent argon and 25 percent CO2).
Many beginners, hobbyists, and professionals prefer to use the MIG welding method as it is the most cost-effective and easier option to go for as compared to other methods.
Choosing the best welding method isn’t that difficult, with the wealth of information, reviews, and common applications easily accessible on the web. Choosing between the push or pull welding method, on the other hand, is far more confusing and thus more difficult of a choice.
There isn’t a clear winner in the welding community as this question has been lingering for a long time, and depending on the location, the answer may be completely different.
Some welders have been using the push welding method for a long time as they believe that it creates a much deeper penetration which in turn results in a stronger weld.
While on the other hand, many other welders believe that pull creates a much stronger weld. With many variables involved, there is no “best for all” and so in this article, we’ll discuss this push vs pull welding and put any misconceptions to rest.
Push welding technique, also known as the forehand technique, refers to the way the welding gun is moved by the welder. As the name suggests, the welding gun is pushed forward, creating welds with unique characteristics.
The direction of your MIG gun is right behind the weld and by pushing along the weld pool (a molten metal residue that is formed), creating a bead. Welding beads refers to the longitudinal progression that is formed when the filler metal is fused together with the base metal.
The technique itself is relatively simple but it results in a weld with unique characteristics and push welding is more suitable for certain projects more than pull welding.
As you might’ve guessed, pull welding is pretty much the opposite of push welding (in terms of hand movement). Instead of pushing through the weld pool, in pull welding (also known as a drag or backhand technique) the welder required to angle their gun directly towards the weld and then drag the gun backwards.
Whether you’re a beginner or not, one of the most crucial steps in welding is the work angle. It is the position of the welding gun relative to the angle of the welding joint. Different work angles will result in different quality welds and thus the welder always wants to find the ideal work angle.
In the MIG welding method, it is highly recommended to hold the MIG gun in a manner that creates a 90-degree angle when welding a butt-joint. This work angle is one of the major differences between the push and pull MIG welding techniques.
Apart from the work angle, the direction in which the gun is being dragged is also different. For instance, in the push technique, your MIG gun is going forwards whereas, in the pull technique, you’re supposed to drag the gun backwards.
The advantages and disadvantages of the push welding technique are very dependent of the welder and the workpiece itself.
Here are some of the most common advantages of the push welding technique:
When you’re moving forward with your welding gun, you’re creating a much flatter and wider weld puddle or pool. This will result in tying more of the base metal with the filler metal and help in creating a tighter bond between the two workpieces.
Because of the wider and flatter weld pool, the weld is much more aesthetically pleasing and polished, compared to the pull weld. However, if you’re a beginner, you’re still prone to mistakes, irrespective of the welding technique. This factor also becomes less important for workpieces were the weld isn’t visible.
However, this also means that the workpiece will require less finishing and the resulting weld is objectively look better and even if looks aren’t something you care very much about, good looking welds are certainly a confidence booster (which is necessary for a beginner’s motivation).
Push welding does not create a deep weld, and while it may sound like an obvious disadvantage – it’s not. In fact, associating flatter and wider welds with weak joints and lower penetration is a common misconception.
Many beginners believe that a deep penetration weld would mean a stronger weld although that may or may not be true depending on the different situations.
For instance, according to a study, a weld’s strength is directly dependent on the completion of the fusion, among other factors, and not necessarily on the depth of the weld.
Here are some of its disadvantages:
Penetration is important and while the depth of the weld will be enough in the majority of the cases, certain projects and workpieces will require greater penetration that may not be possible with push welding. In the case of insufficient penetration, the resulting weld may be weak and pose a threat to safety.
Beginners may not be cognizant of the residual stress levels that the workpiece may have to undergo and use push welding in high-stress situations that may result in the weld breaking apart in the worst-case scenario.
It is important for beginners to keep in mind the fact that due to high pressure, they are required to relieve stress in order to maintain the dimensional tolerance and reduce distortion.
In the past, the rule of thumb for a majority of welders was to use the push technique, however, in recent years, there has been a shift from push to pull technique and here’s why.
In the pull (or drag) technique, welders have greater penetration power and are able to create deeper welds into the base metal as compared to the push weld technique and because of this, the weld is quite narrow, elongated, and stretches upward from the centre, giving it a hill like an appearance.
In most instances, due to deeper penetration into the base metal, the bond between the two workpieces is stronger and much tighter.
Here are a few reasons why not all welders have adopted the pull welding technique:
As mentioned earlier, the pull technique creates a hill like an appearance and has a much-rounded shape as compared to the flatter and wider surface created by the push technique. What this means is that the welder will require more electrode to cover larger joints. This will also be slower.
As the pull technique leaves a less smooth surface, the appearance of the weld isn’t top-notch and the weld might come off as shabby.
Due to the weld being a lot less smooth, welders have to work on it a bit more in order to give it a polished look and smoothen the mound out a little.
Note: It is important to bear in mind that these advantages and disadvantages of both these techniques are dependent on other factors such as the type of metals used, ideal situation, environment, etc, and in most cases, the differences in results yielded by both the push and pull technique are usually not dramatic.
According to a majority of welders, it is believed that when doing a vertical down weld, it is better to go for the push weld technique. In the vertical down weld, welders are required to begin welding from top to bottom.
The welding process can be (and usually is) slow but it’s important to complete the weld without stopping as that leads to the creation of slag in your workpiece. Therefore. this method is a little difficult and time-consuming as it requires more vigilance.
As the pull weld technique creates a much deeper penetration into the base metal, it is often recommended to use it when the workpiece is very thick, heavy, or is expected to work under high load (stress).
An example of a use case for pull welding is bridge construction. The pull weld technique can be quite useful in the filling of the gaps between the beams of a bridge and result in stronger welds.
Although some professionals also believe that there isn’t any “ideal” situation for both the techniques and it mostly depends on the welder and which of the two techniques he is more comfortable with working.
The answer is simple, it depends on the welder and the project. Most professional welders would recommend trying out both the methods first and then figuring out the best-suited option for themselves. You just have to figure out what you’re comfortable with and which of the two is the most efficient for you.
That said, here are some useful points to remember::
One of the most crucial things to remember when either going for a pull or a push technique is the work angle.
Both methods require a lot of concentration as you have to keep a close eye on the stress and slag levels the weld is producing. But since push welding is more prone to slag build-up, welders need to be more careful with push welding.
There is no one definitive answer to this question and it primarily depends on what one technique you’re comfortable with. For instance, after gaining some experience in the field, you may change your preference depending on different situations.
In the welding community, there has been a long-held custom of going for the pull method when there is a lot of slag (a by-product of welding processes). The rule goes like this “If there is slag, you must drag”.
Push and welding have quite a few similarities which can be confusing, especially for beginners. However, once you understand the basics of these welding techniques, it becomes a lot more clear that neither of them is really complicated.
Just remember that there are ideal use cases for each and that your comfort level is one of the main factors when choosing welding techniques.