Welding Basics

With all of the preliminary background information out of the way, we are ready to strike our first arc. It is assumed that you have read chapters 2, 3, and 4 on welding safety and PPE already and that you are familiar with and possess all the necessary PPE and tools required. If not, take this opportunity to do so.

This section describes the techniques you will use when welding with the SMAW process. You will learn the basics of striking an arc and the acronym CLAMS, which stands for Current, Arc Length, Angle, Manipulation, and Travel Speed. This acronym helps us remember the elements of good welding technique and can be applied to every welding process.

Striking an Arc

Once you have your welding machine and workstation set up, you will need to strike an arc to start welding. This sounds simple enough but requires practice to do effectively. The first step in making any weld is actually to make sure you are comfortable. Being comfortable and having freedom of movement along the weld is imperative to making good welds, especially as a beginner. This can take whatever form makes sense to you, as everyone is different. However, consider the following points as general guidelines for good weld posture:

1. If it’s possible to be comfortable while welding, you should be comfortable. try to find something to brace your body or a leg against. Whether you are sitting or standing, try to keep your torso as upright as possible.
2. If the object you are welding can be moved freely, try to position it at a height somewhere between your chest and your waist. This allows you to both see and reach the weld zone easily. If the object cannot be moved, try to position yourself so that the weld you are making is as close to this area as possible. Welding below your waist or above your shoulders will tire you out quickly and makes it hard to see the weld.
3. Hold the “stinger” (electrode holder) in your dominant hand, and then brace that hand with your off-hand. For example, if you are right-handed, you will hold the stinger in your right hand and then brace that hand with your left.
4. Find something to rest the elbow or forearm of your bracing hand on. This can be almost anything. The workbench you’re using, a wall if you are next to one, even a clamp attached to the piece you’re welding. It is important to understand that you don’t need to lean all of your weight on that arm. It is just there to steady you. During welding, everything but the arc becomes dark. Because of this, your brain automatically thinks you are losing your balance and will cause you to sway. Having your arm in contact with a solid object will reduce this effect.
5. Most of the movement during welding should come from your wrists and forearms. You should need to move your elbows and shoulders very little. Try to keep your elbows as low and close to your body as possible.
6. Before actually welding, make a few test runs along the joint to be welded. This is to ensure that nothing will impede your movement when you make the actual weld. You will notice whether your bracing hand can easily slide along the joint without getting caught and if you can reach the entire length of the weld easily. Test runs can also help you to know if are in a good position to see the weld at all times.

Being comfortable during welding increases your stability and range of motion, reduces your rate of fatigue, ensures good visibility, and overall allows you to weld better for longer.

Once you have established your welding posture, it is time to strike the arc. In order to initiate the arc with SMAW you must touch the tip of the electrode to the base metal, then raise the tip slightly above the base metal surface. This is not as easy as it sounds because when you touch the live electrode to the grounded base metal, it creates a “short-circuit” in the flow of electricity, which often causes the electrode to stick to the base metal.

To help keep the electrode from sticking, there are two basic techniques that can be used. In the first, you lightly scratch the tip of the electrode across the surface of the base metal for a short distance, much like striking a match.

This motion should be done quickly and lightly. The more pressure applied, the more likely it will be that the electrode will stick.

In the second technique, you hold the electrode slightly above the base metal surface, then move it straight down and tap the surface lightly before raising it slightly again.

You can think of this motion kind of like striking a pool ball with a pool cue. In fact, many beginners start with this method by holding on to the end of the rod with their off-hand, much like a pool cue. Once the arc is started, move your hand back to brace the other hand.

While these techniques will help with starting the arc, they are not guaranteed to keep the rod from sticking every time. This happens to every welder who uses SMAW at some point, no matter the experience level. Try not to get frustrated if it is difficult to strike an arc right away. With practice, you will become proficient.

Breaking the Arc

Since we talked about striking the arc, we should also discuss how to break or stop the arc. When you come to the end of a weld, the temptation may be to slowly pull the electrode away from the base metal. But this is incorrect. As you come to your stopping point, it is a good idea to hold the arc at the end of the weld for a second or two. This is to help fill in the weld crater. Then, quickly snap the electrode away from the base metal, either in the direction you were traveling or back over the weld. This will efficiently break the arc and prevent any unwanted arc strikes outside the weld zone.

C is for Current

Unfortunately, striking the arc doesn’t fall into our CLAMS acronym, so we must back up for a moment. The first letter, C, stands for current. The moment you turn your welding machine on, you must decide on the type and amount of welding current needed. SMAW uses constant current (cc) welding power. If your welder is a multi-process machine and isn’t automatically set to CC, then you will need to select that now. There will likely be a switch or a button that will allow you to change the type of welding power. Sometimes, instead of CC, you will see a selection labeled “Stick” or “SMAW”. This will set the machine to CC power.

Once you have the correct welding power set, you will need to determine your polarity. Looking at the classification for the electrode you are using, you can determine whether the machine should be set to DCEP, DCEN, or AC. Select the correct polarity by adjusting the switch, knob, or button on the welder or by changing which port the electrode and work leads are plugged into (refer to SMAW Setup in Section 8.2).

You can set your amperage now that you have the correct power type and polarity. Amperage is the most important current setting for SMAW. Amperage has the greatest effect on the quality of weld penetration and weld bead shape. Selecting the correct amperage for the electrode you are using, and the base metal to be welded is very important. For example, a ⅛” diameter E7018 has a recommended amperage range of 90-160 amps (the recommended amperage for each electrode can be found in the product information). However, this must be balanced against the base metal thickness. If you were to weld on a piece of ¼” steel plate, you would find that the appropriate amperage would actually be around 110-125 amps. Thicker plate would take more amperage, and thinner plate would take less. This process of troubleshooting the correct amperage range takes some time and experience. Especially since there are a number of other factors that influence it, which can include welding position, weld joint configuration, the length of your leads, and preheat, among other things. Even the machine you are working with can be a factor, as each different welding machine may run slightly differently.

When on the job, your supervisor can supply you with an amperage range as a good starting point, but you will likely still have to fine-tune your settings from there. The best way to know how to troubleshoot your amperage setting is to practice as much as possible. Look for some of the following issues when welding, which can indicate incorrect amperage:

• If the finished weld bead is narrow, with a high crown and little penetration, your amperage may be too low.
• If the finished weld bead is wide and flat, with excessive penetration and a lot of spatter, your amperage may be too high.
• If the arc is difficult to start and the electrode sticks to the base metal constantly when striking the arc, or if it seems like the arc is almost sputtering out during welding, your amperage may be too low.
• During welding, if the arc digs into the base metal at the edges of the weld or even burns through the base metal, your amperage may be too high.
• During welding, if you notice that the weld pool is excessively long and teardrop shaped instead of oval shaped, your amperage may be too high.

Another control that may be adjusted is the arc-dig or arc-force setting. This setting is not essential for making a good weld, but can help make welding easier. If your machine has this control, you can adjust the “crispness” of the arc. A higher arc-dig setting will make the arc more crisp, meaning it will be narrower and seem to drive more into the base metal, though it does not measurably improve penetration. This is useful for welding in a tight corner or groove or for welding an open root (discussed in Chapter 15: Weld Identification). This also helps keep the electrode from sticking to the base metal when holding a short arc length. Turning the arc-dig down will create a “softer” arc, meaning it will be wider and less forceful. This helps when trying to spread out the weld pool more when welding on a flat surface or welding on thinner material.

Before moving on, one safety note about current settings is that none of the settings or controls mentioned should be adjusted during welding. In some cases, with certain older welding machines, it is even recommended that the machine be powered off before adjusting certain settings like polarity. This is to prevent damage to the machine but ultimately protects you. A damaged machine can cause damage to you.

L is for Arc Length

The second letter of our CLAMS acronym, L, stands for Length. Specifically arc length. Arc length is the distance that the arc travels through the air and is measured from the tip of the electrode to the surface of the weld pool. Arc length is an important welding variable with any welding process, particularly with processes that use CC welding power. In our section about setting the current for welding, you may have noticed that there was no control mentioned for voltage. Both amperage and voltage are a part of every electrical current, so where is the voltage control for SMAW? In a sense, arc length is the voltage control and is manually adjusted by your motions throughout the weld. The distance that the arc must travel through the open atmosphere determines the voltage applied to the weld. As the arc length increases, so does the voltage, and vice versa. This is because it requires more voltage (remember that voltage is electrical pressure or force) for the arc to travel across a greater distance.

Because we are using CC power, the overall electrical power in watts always remains the same. This means that changes in voltage due to changes in arc length will also change the amperage being applied to the weld. If the voltage increases, the amperage will decrease, and vice versa. For example, say you set the amperage on the machine to 80 amps and then maintain an arc length that requires 24 volts. Using the formula from Chapter 5, we know that 24v x 80a = 1,920 watts. At that amperage setting, the welding machine will always try to maintain that 1,920-watt output. If the voltage were to increase to 30v due to increasing the arc length, the amperage would automatically decrease to 64a because 30v x 64a = 1,920w. Conversely, let’s say the voltage decreased to 20v due to holding a tighter arc length. We know that the amperage will instead increase to 96a because 20v x 96a = 1,920w. It is important to note that although this is the theory of how CC welding power works, in actuality, these numbers will not be perfect. This is simply because no welding machine or welding conditions is perfect. However, this provides a close approximation of what actually takes place.

Voltage determines the fluidity of the weld pool. More voltage means the molten metal is more fluid, and less voltage has the opposite effect. What this means to you is how easily the weld pool spreads out across the base metal.

There is a balance that must be maintained using the arc length. If the arc length is too long, the arc becomes violent, and the weld pool becomes too hot and fluid. This usually results in defects like excessive spatter and undercut and poor weld quality in general. Increasing the arc length will not create a weld pool at a certain point but will simply deposit globs of molten metal on the surface of the base metal. On the other hand, if the arc length is too short, the weld will not spread out and will pile up on itself. This leads to defects like overlap (also called “cold roll”) and lack of fusion (lof) because the arc is not hot enough to melt the filler and base metals completely. Further shortening the arc length will result in the end of the electrode sticking in the weld pool.

In general, the correct arc length for most electrodes is said to equal the electrode diameter. For example, if you were welding with a ⅛” E7018 electrode, you would try to maintain a ⅛” arc length. This is easier said than done. You must remember that the electrode is melting off and getting shorter as you progress along the weld. One of the most difficult skills for a new welder to master is to constantly lower the electrode towards the weld pool at a consistent rate. However, with a little time and practice, you will soon be proficient at it.

Arc Blow

Before moving on to the next letter in our acronym, we should discuss a problem that can occur during welding, known as arc blow. Arc blow is a phenomenon that occurs due to the magnetic field created by the flow of electricity through the base metal. It causes the arc to wander haphazardly with little ability for the welder to control it. Arc blow is hard to predict or control because it is related to the shape and joint configuration of the weldment and the amount of welding power flowing through it. It can cause weld defects such as undercut, lack of fusion, and slag inclusions. Some ways to control arc blow are:

• Move your work clamp so that you are welding away from it.
• Use multiple work clamps attached at different points on the weldment.
• Use alternating current if possible.
• Weld at the lowest amperage possible.
• Keep as tight of an arc length as possible.
• Try adjusting the arc-dig to be more crisp.

Though these tips can help, sometimes it is impossible to eliminate arc blow completely. Experimenting with different strategies will help you decide how to best handle an instance of arc blow.

A is for Angle

The next letter in our CLAMS acronym is A, for angle. You may hear this referred to as rod angle or electrode angle (or gun angle for MIG welding and torch angle for TIG welding). Rod angle actually encompasses two different angles: travel angle and work angle.

Travel angle is the angle of the welding rod in relation to the direction the weld is progressing.

There are generally considered to be three different travel angles. A trailing angle is when the tip of the electrode is angled away from the direction the weld is traveling, with the end held by the electrode holder angled toward the direction of travel. This puts the weld pool slightly behind the tip of the electrode, and you may hear it said that you are “dragging” the weld. This is the most common travel angle for SMAW.

A leading angle has the tip of the electrode pointing toward the direction of travel, with the end in the electrode holder trailing behind. This puts the weld pool slightly ahead of the tip of the electrode, and you may hear it said that you are “pushing” the weld. This travel angle is often said to be less desirable with SMAW because of the tendency for slag to be deposited ahead of the weld and then trapped underneath or within the weld as the weld pool passes over it. These slag inclusions are a major defect in a completed weld and might cause it to fail under extreme stresses. While this circumstance is a major concern, experienced welders can make effective use of the leading angle.

A perpendicular angle is a travel angle that puts the electrode straight up and down over the weld pool at 90o to the plane of the weld.

There are different reasons to use any of these travel angles. Welding position has a lot to do with it as well as weld joint configuration. For example, you are more likely to use a leading angle when welding in the vertical up position, but you may prefer a trailing angle for flat or overhead welds. Sometimes the placement of a weld is in such a constricted space that it only allows you to use one angle. Sometimes, the placement will force you to change angles partway through the weld. Another reason you may choose one angle over another is the thickness of the base metal compared to the desired weld penetration. It is generally accepted that a trailing angle produces a weld with deep penetration and a tall, narrow weld face, while a leading angle produces a wide, flat weld with less penetration. A perpendicular angle is somewhere in between.

Whichever angle you are using, it is important to note that extreme angles are generally undesirable. Whether you are using a trailing or leading angle, you should attempt to keep the electrode no more than 15o to 30o from perpendicular.

Work angle is the angle of the electrode in relation to base metal. Work angle is somewhat subjective. The basic idea is that the work angle is used to force weld metal more to one side of the weld than the other. This is not always necessary, so a perpendicular work angle is used to deposit weld evenly. Perhaps the best example of work angle is on a multipass weld, such as in a T-joint or weld groove. Each successive weld pass requires you to adjust the work angle slightly to force the weld one way or the other. Unfortunately, there are no real rules about work angle, and it is something that every welder learns to account for through experience.

The angle of your welding rod is an important factor when making any weld. New welders often have trouble maintaining a consistent rod angle while welding. This is often because they are not familiar with moving the rod and their hands together along the weld joint, while continually lowering the rod as it shortens. Practice finding a comfortable position and being able to freely move your hands along with the electrode holder and rod. In time you will find it easy to keep a proper rod angle.

M is for Manipulation

The next letter in the CLAMS acronym is M, which stands for manipulation. Some people might say it stands for motion. Either way, the focus is on what movement you’re making with the welding rod. This is besides the movement of maintaining your arc length, your rod angle, or your progress along the weld joint. What we are talking about here is what’s referred to as weave patterns or oscillation. The main purpose of manipulating the electrode in this way is to make the weld bead wider. There are a number of different weave patterns or oscillations that can be used. Each one has a purpose, and some are better or worse depending on the situation.

The patterns shown in the image above are just a few of those that have been developed. And simply by modifying a pattern that you are familiar with, you can create a new pattern. There is no rule that tells you which weave pattern or oscillation you should use at any given time or that you need to use any such movement. It is often quite acceptable to make stringer beads, straight weld beads made without side to side motion. It is most often left up to the welder to decide which manipulation they want to use. You will learn through trial and error which ones work for specific situations. It is helpful to ask other more experienced welders for tips in this area.

S is for Speed

The last letter in our CLAMS acronym is S for speed. Speed is the most determinative factor in how big your weld bead is. There are two speeds to be aware of. The first is travel speed. Travel speed is how fast you are progressing along the weld joint. The second is manipulation speed, which is how fast you are weaving or oscillating. Manipulation speed is not a factor if you are making stringer beads.

If you are working off of a welding blueprint, there will almost always be a callout for weld size on every weld (blueprints and welding symbols are covered in Chapter 16). Whether the weld you make is a single pass weld or multi pass weld, your speed is how you will achieve the weld size. A slower speed will make the weld bigger, and a faster speed will make it smaller. Adjusting your speed is the best way to control the size of a weld. A general rule for SMAW is that you want the weld pool to be approximately twice the diameter of the electrode you are using. For example, if you are using a ⅛” electrode, you would want to keep the weld pool about ¼” wide.

If your speed is incorrect for amperage and size of rod you are using, it can cause weld defects. A speed that is too fast will often cause undercut at the edges of the weld. Too slow of a speed will likely cause overlap. Paying close attention to the weld pool as you are welding will help you determine how fast or slow you should be moving.

The Importance of the Weld Pool

Now that we have finished our CLAMS acronym, I think you will agree that there is a lot to pay attention to during welding. Being able to bring each part together simultaneously is one of the biggest challenges for new welders. It’s best to start small and try and focus on one thing at a time until you get the hang of it. For example, spend a whole training day just striking an arc, and the next day focus on your arc length, and the next day focus on your angle or travel speed, etc. Learning to weld takes a considerable amount of patience but if you are diligent and stick with it, you will be surprised how quickly you will improve.

That being said, you need to pay attention to one more aspect of making a weld, and it is quite possibly the most important. That is being able to see and read the weld pool. Whatever else you do, you must be able to see the weld pool. If you cannot see the weld pool, you must change whatever you are doing that is keeping you from seeing it (this cannot be stressed enough).

This is, by far, the most difficult thing for a new welder to do. Often, inexperienced welders will look at the arc or their rod as the focal point of their vision. But you must train yourself to watch the weld pool and see everything else through your peripheral vision. Good welders know that the weld pool will tell them everything they need to know about how the weld is going. This is true of any welding process.

With SMAW, the weld pool should be roughly oval or egg-shaped. If the weld pool is elongated or has turbulence on the surface, that can mean that you are running too hot and need to turn down your amperage. A narrow weld pool can indicate an amperage that is too low or a travel speed that is too fast. An overly wide weld pool can mean a travel speed that is too slow. A weld pool that is off to one side of the electrode can indicate a bad work angle.

Practice learning to read the weld pool. Ask questions of instructors and other welders if you don’t understand something about it. Once you can effectively interpret what the weld pool is telling you, you are well on your way to being a better welder.

Special Safety Considerations

Before we conclude this chapter, it would be a good idea to go over some safety considerations that are commonly associated with SMAW.

As you may expect, some of the most common safety hazards will be smoke, sparks, hot metal, sharp edges, and electricity. Protect yourself from these things by wearing the appropriate PPE and being aware of your environment. Use a respirator to help with smoke. Wear thick gloves, a leather or cotton jacket, and a cotton hat to protect from sparks, hot metal, and sharp edges. Look out for damaged welding leads or other exposed electrical components that may present the hazard of electrical shock. Also, remember that the light produced by the welding arc can burn your skin and eyes. Always keep your skin covered while welding, and make sure your welding hood has the correct shade of lens for the process. For SMAW, a shade 10 is generally recommended.

With SMAW, there are some specific things that you should keep in mind. Remember that when the machine is on, the electrode holder is always live. Damaged electrode holders can have exposed contact surfaces that could accidentally strike an arc if touched to the base metal. This also means that any time an electrode is held in the holder, the electrode is live. Never set the electrode holder down with an electrode still loaded in it. Be aware of any broken flux on the electrodes. Any place where the flux is broken off exposes the metal rod underneath and presents the potential for an accidental arc strike. Aside from being dangerous, unintentional arc strikes on the base metal are undesirable. In many welding situations, arc strikes outside the weld zone are considered a defect and may cause the piece to be scrapped.

Another problem related to arc strikes is the end of the electrode getting stuck when you attempt to initiate the arc. This is a common occurrence with SMAW. However, new welders might be surprised by it the first time it happens. Be aware that if the rod sticks, the electricity continues to flow through the circuit even though there is no visible arc. This can be hazardous for two reasons. One, the machine is now operating at the working amperage and voltage. You would not want to touch any of the contact points and become part of the circuit. Two, if the electrode is not immediately broken off the surface of the base metal, it will begin to heat up. After a few seconds, you will see it glow bright orange. The rod is now in excess of 1,500o F. You would not want to touch the rod at that temperature, even with a gloved hand. If you find that you cannot easily break the electrode off the base metal when it sticks, the next best thing to do is to let go of the rod with the electrode holder. Then wait about ten seconds and you should be able to easily snap the electrode off of the base metal.

There are a few final things to be careful of. If you are in a situation where you are welding full-time or at least several hours consecutively, beware of fatigue. Welding is a physically and mentally demanding job, and fatigue can set in without you noticing. Take breaks at appropriate times, keep yourself hydrated, and be aware of heat stress and heat stroke. If you are working with metal being heated to thousands of degrees, it is going to get warm in your area. People are the most careless and at risk for an accident when they are tired. Always try to find a way to be as comfortable as you can. This will help delay the onset of fatigue. There is one particular practice you want to avoid, though. The electrode holder and the welding lead are heavy. Over time your arms will start to feel strained. The temptation is to wrap the lead around your arm or body. While it is fine to simply drape the lead loosely over a shoulder, avoid wrapping the lead around yourself in a coil. A coiled copper conductor with electricity running through it is an electromagnet, and in this case, with you at the center of it. High levels of electromagnetic flux have been shown to be dangerous to humans.

As with any industrial environment, there are always hazards present in welding. Yet many thousands of welders perform their work every day without incident. These welders know that the best safety practices are to be competent, have common sense, and be aware of your environment.

Attributions

1. Figure 8.25: Shielded Metal Arc Welding by Weldscientist is released under CC BY-SA 4.0
2. Figure 8.26: Striking the Arc by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
3. Figure 8.27: Welds at Different Amperages by David Ridge, for WA Open ProfTech, © SBCTC, CC BY 4.0
4. Figure 8.28: Arc Length and Voltage by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
5. Figure 8.29: Volt/Amp Curve by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
6. Figure 8.30: Electrode Angle by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
7. Figure 8.31: Travel Angle by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
8. Figure 8.32: Angle and Weld Profile by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
9. Figure 8.33: 15-30 Degree Angle by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
10. Figure 8.34: Work Angle by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0
11. Figure 8.35: Weave Patterns by Nicholas Malara, for WA Open ProfTech, © SBCTC, CC BY 4.0