When they’re learning to weld, most people use scrap pieces of mild steel. Mild steel is easy to work with, relatively consistent, and very forgiving of a beginner’s mistakes. It’s also fairly common in the wild and will be a frequent target for welding, so it’s good to learn the practicalities right away.
Aluminum is a different story entirely. It shows up in construction, automotive uses, and many more. Aluminum is used all over the place because it’s corrosion-resistant, relatively durable for its weight, and exceptionally lightweight. It also forms alloys with other metals quite well, generally introducing a variety of properties that can be beneficial in specific uses.
The trouble is that many of aluminum’s benefits are also why it can be tricky to weld. Welding aluminum presents several unique challenges, including:
Despite its qualities, aluminum requires more heat than mild steel to weld properly.
The weld puddle for aluminum looks very different than steel, so your visual cues will be different.
It’s surprisingly easy to burn through aluminum and drop your weld pool right through the material, especially with thinner material.
Different alloys require different kinds of filler to weld properly, and picking the appropriate filler can be difficult.
Welding aluminum is often considered difficult, but it’s not necessarily as tricky as it is different. If you’re used to working with mild steel, you’ll need to break yourself out of your habits and turn off your mental auto-pilot to weld aluminum properly.
Can You MIG Weld Aluminum?
MIG welding is entirely possible to use on aluminum, yes. Most professionals recommend TIG welding if possible, but MIG is perfectly acceptable (if a little more challenging) to get right.
Depending on who you ask, MIG might be better for thinner metal gauges, or TIG may be the preferred method.
This decision is largely down to preference and the comfort level of the welder; if you’re a beginner, TIG may be a better alternative if you have the equipment.
The key is the type of aluminum you are welding and the type of welder you have. Aluminum is a generic term and refers to many kinds of alloys, which we’ll get to here in a bit. If it’s an alloy compatible with MIG welding, you can weld it with a MIG gun.
What Equipment is Necessary to MIG Weld Aluminum?
If you’re planning on MIG welding aluminum, you must get your equipment and tool settings configured before you begin. Otherwise, you risk the metal not reacting as you expect, and the whole project can fail in various ways.
What do you need?
1. Cleaning Tools
One of the essential parts of welding aluminum is ensuring that the surface you’re working with is clean. This step is only sometimes necessary for particular welding projects and metals, but it’s a requirement for aluminum.
Aluminum oxides are much more heat-resistant than plain old aluminum or aluminum alloys. If there are any oxides on your work surface, the heat from your welder will melt the aluminum, but not the oxides. The aluminum melts at around 1200 degrees, while the oxides don’t melt until a whopping 3700 degrees! Those oxides will sink into your weld puddle and create inclusions, pockets, and weak spots in the weld.
Cleaning is also essential when welding aluminum because the oxide coating on aluminum can make it more challenging to adhere to. You may need to use a wire brush or sandpaper with your wire wheel for the best results.
After removing dirt, corrosion, and coatings, you must clean both of the parts you want to join with solvent or soapy water.
Not only is it critical to clean your surface before welding, but it’s also just as important to clean it the right way. For example, a steel brush can contaminate the surface just as quickly as if you left it dirty. An aluminum brush is recommended, and you’ll want to be careful with softer aluminum to ensure that you don’t muddle over inclusions rather than brush them away.
2. Filler Rods of the Proper Alloy
Selecting the right filler rod can be a significant chore. The wrong alloy can leave your weld susceptible to cracking or breaking, weaker than the joint should be, or otherwise not suitable for the job.
Choosing the appropriate alloy filler depends on the answers to several questions:
What is the base designation of the materials?
Does your weld need to withstand prolonged high temperatures?
Will the weldment be anodized when completed?
Does your weld have specific flexibility, strength, or toughness considerations?
Will it need to be heat treated?
These questions and a chart like this can help you decide what filler is best for your job.
That said, this is a beginner’s guide. That means you’re likely welding practice materials or learning directly from a mentor with more specific, practical advice. Everyone who teaches welding has their concept of what is most important, so be sure to ask them for specifics if necessary.
To further narrow things down, filler rods 4043 and 5356 generally apply to a vast majority of aluminum welding applications. It’s not perfect – there are certain situations where other rods will be necessary – but keeping those two on hand will cover many of your bases.
If you’re curious about the designations for filler rods, here’s a rundown. In short:
1XXX is close to pure aluminum.
2XXX is a copper alloy primarily used in heat treatment welds.
4XXX is a silicon alloy and is extremely common in various forms.
5XXX is a magnesium filler typically used in high-strength welds.
Each has numerous pros and cons, so choosing the appropriate filler is critical in many applications.
3. The Right Gas
Picking the correct gas is also vital for welding aluminum. Your choice of shielding gas will be a primary factor in the quality of the resulting joint.
For the vast majority of projects, the go-to choice is Argon gas. 100% pure Argon is a good shielding gas because of its ionization potential and ability to keep a weld clean.
The alternative, used by many pro welders, is a mixture of Argon and Helium. Helium offers a more significant ionization potential and thermal conductivity, making for broader, deeper welds. As a beginner, a wider, deeper aluminum weld is much more likely to burn through, so stick with Argon until you’re comfortable with it. Helium is best added to the mix for more extensive, thicker pieces of aluminum where weld depth and penetration are required.
The critical piece of information here is that using CO2 in your gas mixture won’t work, which is why many attempts to MIG weld aluminum fail.
4. What Settings are Best for MIG Welding Aluminum?
Properly configuring your MIG welding equipment is also important.
First, set your gas flow rate properly. You need enough gas flow to shield your weld correctly. Since you’ll be moving reasonably fast, a flow rate of around 20-30 cubic feet per hour is the general range to work in.
Second, the voltage of your welding gun should be appropriately configured. Usually, a voltage of around 21-24 is ideal. You’ll also want to ensure your MIG gun is set to DCEP (Direct Current Electrode Positive) polarity for the proper process.
Finally, welding aluminum is best done with the spray welding procedure. With this procedure, your arc is constant, and tiny molten filler droplets are sprayed from your gun along the arc and onto your weld surface.
Another common issue beginners run into is a cheap welding gun that jams rather than smoothly feeding the filler wire. Your gun needs a fast feed speed for its filler for this process to work correctly. Wire feed settings can also vary depending on the thickness of the wire you’re using.
5. What’s the Right Technique for MIG Welding Aluminum?
Welding aluminum is a high-heat process. Aluminum melts quickly, but it’s very thermally conductive, so the heat dissipates just as readily. This characteristic means it’s susceptible to variations in movement, and if you move the wrong way, your weld won’t work.
Proper aluminum welding requires three things.
First, you need a fast travel speed. This requirement is due to the heat involved; if you linger too slowly as you move, you’ll put too much heat into your materials, and risk burn-through. This scenario is prevalent with newbies attempting to weld aluminum. The travel speed required is much faster than with steel, and it will feel uncomfortably fast until you get used to it.
The second requirement is using the forehand technique. Where a backhand technique angles the gun away from the direction of travel, this does not facilitate good shielding gas coverage when you’re moving as fast as you need to. That means regular air will get into the weld pool and contaminate it. The forehand technique, where you tilt the gun 15 degrees toward travel, ensures proper shielding.
Third, you want to use simple weave patterns as you weld and avoid complex patterns. Using zigzag, looping, or other welding patterns is a technique used on steel to widen a weld and let heat linger a bit longer to increase depth.
Both are bad when welding aluminum and dramatically increase the risk of burn-through.
In cases where you’re welding thicker pieces of aluminum or need a larger fillet weld, multiple straight passes are better than an attempt at a wider weave.
My Weld is Bad: What Went Wrong?
If you’ve tried out a few aluminum welds using the MIG process and had mixed results, there are a lot of possible points of failure to diagnose. You can start by narrowing it down based on what went wrong.
1. Your weld burned through.
Burn-through or melt-through is caused by excess heat in one spot. There are numerous possible causes, but the most common for beginners is moving too slowly across the joint. Even if you think you’re moving fast enough, it’s likely that you aren’t.
It’s also possible that your joint type isn’t appropriate for the project. Instead of using an edge joint, you may benefit from a corner joint instead, or vice versa. This decision is very situational, however. Similarly, using thicker materials as a base might be appropriate, though you don’t always have a choice.
For more significant welds, you may need to work in shorter bursts to allow the material to dissipate some heat along the way.
2. Your welds are dirty.
Reactions or inclusions in the weld pool usually cause dirty welds.
First, check to make sure you’re using the proper technique. Forehand or push welding is necessary to properly shield your weld as you move, and if you don’t have the angle correct, you’re likely to end up with very dirty welds.
If you’re using the correct technique, it’s possible that your voltage needs to be higher, particularly considering your amperage. You won’t get a spray transfer without sufficient voltage, and your weld won’t work.
Also, make sure you’ve correctly cleaned the surface using aluminum-only tools. The wrong kind of tools will leave particulate matter behind that will cause inclusions in your weld.
Finally, double-check to ensure you’re using the correct shielding gas and filler rod. If either is incorrect, your welds will end up pretty bad.
3. Your welding gun gums up.
Two common problems can crop up, particularly with low-quality MIG welders.
First, the filler material burns back into the gun and causes problems. This scenario usually occurs if you haven’t maintained the proper tip-to-work distance along your weld, or right at the end of the weld.
There are a few “cheats” you can use to get this right, so talk to your mentor about it.
The second is when the feeding process for your filler wire is unsteady or prone to coiling up behind the gun, known as birdnesting. There are several common causes of this, which you can read more about here.
Putting It All Together
Many people claim that MIG welding aluminum is impossible. Some have never attempted to weld aluminum because they believe it is, and they are intimidated by it; others have had a bad experience trying. Others say so to warn off beginners from doing something much more challenging than welding steel. The truth is that MIG welding aluminum is possible; it’s tricky and requires proper settings and technique, but it’s easier than the rumors make it out to be.
However, since there are so many ways that aluminum welding projects can go wrong, it also requires practice and training to get them right consistently.
“Welding” is any method of joining two materials together. While welding often refers to joining metal pieces, welding can apply to other materials, including plastic and wood. Because of this variety, numerous kinds of processes are used to weld materials together. Even something as simple as glue can be considered a welding method.
However, we’re not concerned with those sorts of welds today. Instead, we’re talking about welding metal. With metal welding, you might use four main processes in a typical shop: MIG welding, TIG welding, Stick welding, and Flux-core welding.
These four kinds of welding are called “arc welding” since they use arcs of electricity as the key to their processes. Setting MIG and TIG aside, let’s discuss Stick and Flux-core welding today.
Gas and Slag
Two essential elements of arc welding are the use of gas and the production of slag. These are critical differences between MIG and TIG welding and Stick and Flux-core welding.
MIG and TIG welding is known as “gas welding” because they use a shielding gas. The shielding gas creates an isolated atmosphere around the work area, which pushes away environmental oxygen, hydrogen, moisture, and other reactive substances that would otherwise penetrate, react with, or compromise the weld. We’ll cover that in greater detail in another post.
In MIG and TIG welding, gas is fed through the welding gun, shielding the area with its isolated atmosphere. Conversely, stick and flux-core welding produce their own gas on-site using flux.
Flux is an additive used to help promote clean, smooth welds. It does this in two ways:
Flux burns into a gas, which creates a shield similar to the shield pumped in by MIG and TIG welding.
Flux melts in place and floats to the top of a heated work area, shielding the molten weld from environmental impact as the shielding gas dissipates.
The melted flux that hardens on the outside of a weld is known as slag. This slag is excess material typically cleaned off the weld when the weld is completed.
So, the primary difference between gassed welding (MIG and TIG) and gasless welding (stick and flux-core) is the presence of flux.
A few considerations with gasless welding make it more practical for specific projects than cleaner gassed welding:
Since the gas is produced in situ, gasless welding can be done outdoors in windy conditions that would interfere with shielding gas from gassed welding.
Because slag is produced from burning flux, welders using gasless welding must always pull the electrode to avoid pushing slag too deep into the weld and creating slag intrusions, which compromise the integrity of the weld.
Gasless welding creates many more fumes than gassed welding, making it potentially more dangerous to use in enclosed spaces or spaces without adequate ventilation.
These are concerns with both stick and flux-core welding alike. So, what are the differences between stick and flux-core welding?
How Stick Welding Works
All forms of arc welding use a similar process. This process uses electricity to heat two pieces of metal into a molten state.
They also use a filler rod that melts in the same place. The three metals (piece one, piece two, and filler) melt together and solidify into a single strong joint.
One of the primary differences between the four kinds of arc welding is what filler material is used. The filler (or the “stick”) is a metal rod coated in flux in stick welding. This composition is why stick welding is called SMAW or Shielded Metal Arc Welding; the filler metal is shielded.
Electricity melts the joined materials and the stick with its flux coating, producing slag and a shielding gas on-site.
The Pros of Stick Welding
Stick welding has various benefits over other kinds of welding, which offset the cons we’ll discuss briefly.
First of all, stick welding can be very versatile. A wide range of electrodes can be used for different purposes and welds, lending them a lot of flexibility and utility. You can find stick welders that work off either 110v or 220v, and they’re pretty compact and easy to travel with.
Stick welding is also not very expensive.
Filler rods are pretty cheap, and since you don’t need inert gas tanks, you also save on that expense.
Stick welding can be used on metals that haven’t been thoroughly cleaned and prepared and can still produce a quality weld.
Another benefit is that stick welding is the least sensitive to contamination. It requires much less prep time than other forms of welding.
The Cons of Stick Welding
Stick welding is only perfect for some projects; if it were, there would be no need for other kinds of welding.
Stick welding is the most sensitive kind of welding to the skill of the welder. The resulting weld truly shows the skill level of the person welding the joint in terms of the presence of slag, the evenness of the weld, and other qualities.
While stick welding is resistant to contamination and dramatically reduces the need to prepare metal before welding, that savings is eliminated by post-welding cleanup.
Stick welding produces the most significant amount of slag out of any welding, so cleaning off slag is a considerable investment. Moreover, for multi-pass welds, you must clean them between each pass.
Stick welding can also burn through electrode sticks quite quickly. For longer welds, this means taking a break to switch electrodes in the middle of a weld, meaning you need to be able to tie your welds together appropriately.
Overall, stick welding is one of the most skill-intensive kinds of welding and the most prone to showing your mistakes.
How Flux-Core Welding Works
The primary difference between stick welding and flux-core welding is right there in the name; it’s all about the composition of the electrode. With stick welding, you have a metal electrode coated in flux. With flux-core welding, you have an electrode made out of flux coated in metal.
While it might not seem like this would make a huge difference – after all, both ingredients are right there in the rod – it’s pretty impactful.
In addition to the above, flux-core welding can only be used on ferrous materials like cast iron and mild steel and cannot be used on non-ferrous materials like aluminum.
In many ways, flux-core welding can be compared to MIG welding, while stick welding is comparable to TIG welding. It’s easier to learn and somewhat more forgiving than its counterparts.
The Pros of Flux-core Welding
Flux-core welding has benefits that make it useful in certain situations.
Like stick welding, flux-core welding is ideal for windy conditions. It’s also great for welding materials with surface impurities that you can’t easily remove, like paint or rust.
One of the best benefits of flux-core welding is that it has a lot of leeway in arc distance and related factors. It can automatically adjust for changing conditions and correct for an unsteady hand.
This feature makes tackling specific projects more straightforward and approachable than stick welding.
Flux-core welders are also the most portable. You can plug them into a standard household 120v power supply, and since they do not need a gas tank, you can quickly move them from place to place.
The Cons of Flux-core Welding
Flux-core welding has a few drawbacks in addition to its benefits.
First of all, it’s the smokiest of the welding types. It produces the most smoke and gas and thus requires a well-ventilated or outdoor space to weld to avoid dangerous conditions.
It also produces the most heat. This quality makes it difficult to weld thinner materials and impossible to use on the most delicate metals because it will burn through them.
Also, like stick welding, flux-core welding produces a lot of slag and spatter, which must be cleaned up when the weld is complete.
Finally, flux-core welding is somewhat more expensive than stick welding. This difference is almost entirely because flux-core wires are more difficult to produce and, thus, more costly than flux-coated wires.
Comparing Stick and Flux-Core Welding
Leaving MIG and TIG welding out of the comparison, it’s easy to compare stick and flux-core welding directly.
1. Weld Quality
In terms of weld quality, both stick and flux-core welding heavily depend on the welder’s skill. All else being equal, stick welding will generally produce a slightly better weld, but both are more or less comparable. It’s also easier to weld in less-than-ideal conditions (such as when you have no time or ability to prep your metal) than MIG or TIG welding.
2. Welding Speed
Two different rates of speed can be necessary for welding: the weld’s speed and the filler material’s deposition rate. A slower deposition rate means a slower weld, but a faster deposition rate doesn’t necessarily mean a speedier weld; it can also mean a deeper or more thorough weld.
Stick welding is among the slowest welds in terms of speed and deposition rate.
Flux-core welding can be quite fast, allowing you to make emergency repairs and spot welds much quicker than other welding methods.
3. Heat Control
One of the most significant risks of welding is burning through the materials you’re trying to join, especially if those materials are thin. A welder must be able to control the heat used in the weld to prevent burn-through.
To an extent, different kinds of joints and joint preparations (such as bevels or J-grooves) can help mitigate this, but it’s very situational.
Stick welding has a slight advantage in terms of heat control. Flux-core welding is a hot process that relies more on movement speed to avoid burn-through.
4. Visibility of Work
One of the most significant drawbacks of flux-core welding is the high amount of smoke produced by the burning flux. While this is part of the shielding around the weld, it’s also the cause of a significant reduction in visibility. This drawback means that working in tight conditions, on narrow welds, or in places where precision is necessary, it can take time to get a good weld going with flux-core welding.
Stick welding is also not idealfor smoke and visibility, but it’s better than flux-core welding. Visibility is generally best with gassed systems, however.
Gassed systems are less portable than gasless systems since they require you to lug around cans of gas, additional hoses, and other tools. Between stick and flux-core welding, stick edges out in portability, as it needs less in the way of electrodes and other materials.
6. General Utility
Stick welding can be used to weld nearly anything. In many cases, the primary change you need to make is to the stick you’re using.
Sticks come in a wide range of different sizes, compositions, and styles, to facilitate all manner of welding.
Flux-core welding, on the other hand, is almost entirely limited to a few ferrous materials and thicker materials at that. While you can purchase some additional forms of electrodes for different kinds of welding, it’s generally more effective not to use the wrong tool for the job.
What Type of Welding is the Best?
This question is common among novice welders and newcomers to the trade. The truth is, there’s no single “best” kind of welding.
Each kind of welding has its pros and cons for the project, and the type of welding you use largely depends on the project, the materials, and the needs of the weld. Some welds perform better under stress, some are best used when the materials aren’t able to be prepared, and some are decorative.
Skilled welders learn at least the basics of all four kinds of welding to have a solid base of skills to use whenever welding is necessary.
Are you interested in learning how to weld using a gasless method? If so, consider renting equipment from us. We have an extensive range of welding machines, including flux-core and stick welders. If you’re unsure which welder you need for your project, contact us today, and we’ll point you in the right direction!
Corner joints are ubiquitous among the five primary types of joints in welding. Learning how they work and how to implement them properly is an essential part of learning how to weld, whether as a hobbyist or as preparation for a welding career.
Welding can range anywhere from simple joins and primary connections to fantastically elaborate art, but it all boils down to a small handful of techniques leveraged with mastery. Even master welders needed to start somewhere, and that somewhere is learning the different kinds of joints. Of the five types of joints, the Tee Joint is among the easiest to understand.
Welding can range anywhere from simple joins and primary connections to fantastically elaborate art, but it all boils down to a small handful of techniques leveraged with mastery. Even master welders needed to start somewhere, and that somewhere is learning the different kinds of joints. Of the five types of joints, the Tee Joint is among the easiest to understand.
What is a Tee Joint?
Different welding joints refer to various positions and angles of the two pieces of material being welded together. Tee joints are one of several kinds of joints, including butt joints, lap joints, and others.
Tee joints, also known as T joints, refer to the shape of the materials making a perpendicular connection, like a T. It doesn’t have to be precisely 90 degrees, but a right-angle connection is by far the most common. Though deceptively simple in shape, you can make tee joints with various weld types.
Tee joints are most often used when the requirements are simple: two materials need to be connected perpendicularly and aren’t shaped oddly. They are also common in machine applications and structural welding. Think table legs attaching to a table or pipes to a cross-member for a railing.
A tee joint may be welded on one side of the material, or it can be welded on both sides. For example, when joining two flat pieces of metal, both sides of the vertical member are easily accessible and can be welded. When joining a pipe to a flat surface, the outer side is accessible, but the inner is not. Additionally, for added penetration and strength, the weld may use plugs from the back side of the cross-piece.
The Difference Between a Weld and a Joint
In welding, it’s important to distinguish between a weld and a joint. Both are essential to any connection, and knowing which to use in which situation is part of learning and mastering welding.
A weld is a method in which two materials are joined, and any grinding or drilling is necessary to prepare the materials. Different kinds of welds lend different types of strength to the resulting joint. The most superficial tee joints are welded using a primary fillet weld; the materials are placed against each other, and the weld adheres them together. More complex versions involve beveled welds, J-welds, plug welds, slot welds, or melt-through welds.
So: a joint is the position of the materials, and a weld is how they are connected.
The needs of the finished product largely determine the choice of the weld. For example, a simple fillet weld is usually satisfactory if the joint is mainly cosmetic and does not need a high degree of strength. Conversely, if the joint is expected to bear significant loads or withstand lamellar tearing, more thorough preparations will be necessary.
The Pros and Cons of a Tee Joint
Tee joints are simple joints with many avenues to make them more complex and robust.
Typically, a tee joint is simple and relatively easy/fast to produce. When done correctly, tee joints can be pretty strong. However, they must be done correctly; if the materials are thick, you must prepare the edges, and additional support may be necessary.
The most significant risk is lamellar tearing, where the base material cracks due to inclusions and imperfections in the metal, and the contraction is caused by the welding heat. Lamellar tearing occurs because of tensile stress, which can limit the utility of the tee joint.
Tee joints can also be deceptive. With basic fillet welding, a joint can look and feel solid while only being adhered to on a surface level, meaning the joint will be prone to failure. With thicker materials or materials that will need to bear the stress, you must ensure that proper penetration into the metal fully adheres to the pieces.
How to Weld a Tee Joint
Welding a tee joint is simple, and it’s often a great introduction to welding. Here’s how to do it. For this article, we assume that you’re using an appropriate kind of welding (between stick, TIG, and MIG) and that you have the necessary equipment. If you’re still learning, your mentor should be able to provide you with what you need.
As a quick primer:
Stick welding is the oldest process and involves consumable sticks of electrodes. It’s cheap, versatile, and easy but also prone to molten spatter and slag, requiring more finishing. Stick welding is also the best outdoors and requires the least cleaning.
MIG (Metal Inert Gas) welding uses an automatic feed process for its electrode and shielding gas to protect the weld from atmospheric contamination. It’s easy to learn but more expensive and often requires enough equipment that there are better choices than this if you need a portable solution. It also requires more pre-weld cleaning.
TIG (Tungsten Inert Gas) welding is the most complex and high-skill version of welding, most used by artists and artisans. It provides the cleanest and strongest welds but the most coordination and care and the most preparation.
Picking the right kind of welding is essential. However, as a beginner, you will likely be starting with either stick or MIG welding and learning the ins and outs of the process before digging deeper into the most appropriate kind of welding for each job.
Step 1: Safety
Welding, when done correctly, is a safe process for both hobbyists and career practitioners. However, it has many different ways to go wrong, so safety is paramount.
Make sure you have an appropriate safety checklist before starting any weld.
Ensure you have the appropriate safety equipment, including welding gloves, a helmet or mask, a jacket or apron, and work boots. You may also consider a respirator, depending on the kind of welding and the location where you’re working.
Work in an appropriate location, outdoors, in a welding shop, or in an otherwise safe area. Be wary of nearby flammable objects, and make sure you have safety tools, such as a fire extinguisher, fire blanket, and eye wash bottle.
Ensure proper ventilation when welding.
Take care of electrical safety, and ensure your equipment is in good working order.
Welding safety is critical, so take this step, no matter how deep into welding you delve.
Step 2: Prepare Your Materials
Impurities are the enemy of solid welds. Before welding metal, you must prepare that metal. There are two kinds of preparation; you must do the first for every joint, and the second depends on the type of weld.
To prepare your materials, you’ll need an angle grinder to remove surface materials, mill scale, dirt, paint, and any other impurities that can get between the two pieces of metal and your filler material. Remember lamellar tearing? Lamellar tearing can be minimized or avoided in various ways, including cleaning. Welding two pieces without adequately cleaning them will result in those impurities baked into the weld, weakening it for inevitable failure.
It’s also a good idea to clean a spot for your ground clamp to ensure a solid connection and reduce the risk of stray shocks.
At this point, you would typically be thinking of what kind of joint to use, but as we’re discussing tee joints, that choice is made for us. So, now you must consider what type of weld to use.
Fillet welds do not require further preparation of the materials and are best used when strength is not needed or when the materials are thin.
Beveled welds grind a straight, diagonal cross-section from the vertical member of the T, creating more space for the filler metal and deeper penetration. These are commonly used when a stronger weld is needed and for pipe welding.
J-welds are similar to beveled welds, except they leave more material at the curve of the J. This technique gives the weld more strength, similar to the beveled weld, but leaves more material in the contact surface, so there’s a more significant margin of error.
Plug or Slot welds involve drilling or grinding holes in the flat member of the T to create plugs or slots of filler material to lend additional strength to the joint. These require further preparation but form a stronger joint.
Note that the choice between a J or a V bevel primarily comes down to the tools you have on hand. A J is usually better if you have a tool to produce the bevel. J welds are slightly more robust and easier to do but are harder to bevel by hand uniformly.
Basic fillet welding is fine for practice welds or simple bevels to practice something more complex.
Step 3: Take Position and Tack Weld
High-quality welding requires even, thorough, steady handling of your welding gun. To facilitate this, you want yourself and your materials to be positioned such that you need to move as little as possible to perform the weld. Practice moving the gun across the weld, maintaining a steady hand. Reposition if you encounter something in your way or would otherwise need to reposition mid-weld.
Next, you’ll want to secure the two pieces using a tack weld. Tack welding is performed by making small dots of weld to hold the materials in place for the final weld. This step is also your last opportunity to verify accurate positioning, angles, and squaring of the materials. No one wants to weld a T only to find it looks more like a 7!
After you have tacked the vertical member in place, you are ready to begin the final weld.
Step 4: Lay the First Bead
You move your welding gun over a joint and deposit filler material when welding a joint. The pattern in which you do this is called a bead. The simplest bead is a stringer, a single straight bead across the joint being welded.
Different kinds of beads allow you to create more comprehensive welds and better control the heat in your weld. For example, this image shows multiple motions, such as waves, triangles, and ladders:
A simple stringer bead is all you need for a practice weld and a beginner welder. Later, you can practice other kinds of beads, different positions for welding, and different circumstances in which welding can go wrong. After all, it’s just as important to know how things fail as it is to understand how they go right, so you can recognize it and learn to adjust.
If your materials are particularly thick, you may need to lay more than one bead. You may also need to return to step 2 to re-clean the weld for a second pass to prevent slag from contaminating and weakening the joint.
Step 5: Grind and Finish
Once your weld is complete, it’s time to finish it.
If your weld is not going to be visible, or if the overall look of the weld doesn’t matter, then you’re done. Unfinished welds can look beautiful in the hands of a professional, but they may also be susceptible to rust when exposed to the elements. Welds are often the first area in construction to rust.
So, you may need to finish the weld. Completing a weld can involve:
Grinding the weld to remove slag left over from the welding process (particularly with stick welding).
Grinding to smooth out unevenness in the weld itself (which is familiar with beginners and those with trouble keeping steady hands.)
Paint and other treatments for the finished product.
If you are planning to grind your joint, you should exercise caution. It’s effortless to over-grind and to weaken (or even remove) your weld entirely, separating your pieces and leaving you back at square one. While that can give you a good source of another round of practicing, it’s not a habit you want to get into.
Welding is an essential skill for any tradesperson, and at the same time, it is one of the most satisfying. There are many different types of welds, but the tee joint is one of the most common, so if you’ve been looking for a good beginner’s guide, this should help.
Airborne contaminants can foul heat exchanger fins over time resulting in reduced efficiencies and heat exchange capacity. Traditional cleaning methods such as liquid foam and caustic chemicals have fallen out of favor in exchange for more environmentally friendly technologies such as dry ice blasting.
Recently, an oil refinery in New Mexico needed to perform an emergency cleaning on their heat exchangers due to the fins being clogged. The heat exchangers were cleaned using dry ice blasting which allowed the fin banks to be put back into service immediately after the cleaning process was completed since there was no required dry-out period typically associated with wet cleaning methods (drastically reducing downtime).
In addition, since the fin banks could be cleaned one at a time, additional time was saved since the cleaning could be performed in stages, which allowed banks that weren’t being cleaned to remain in operation. The dry ice blasting process proved superior for cleaning the radiators, recapturing improved heat transfer efficiencies, negating waste creation conventionally associated with maintenance cleaning, reducing containment/disposal costs, and improving heat exchanger operation and safety.
The Red-D-Arc team provided a complete solution for the project including: rental dry ice blasting equipment, portable compressors, dry ice supply, as well as on-site support personnel to provide training and application advice. Dry ice blasting provides a higher quality of clean, reduces the risk of damage, uses no water, aligns with sustainability models, and consumes recycled CO2 byproduct in the form of dry ice making it a carbon neutral option in today’s increasingly environmentally conscious world. Heat exchangers aren’t limited to the oil and gas sector, and are used across a wide range of industries.
To find out if dry ice blasting and cleaning could deliver a superior solution to your current or future cleaning requirements, please contact a Red-D-Arc representative today.
Airgas, an Air Liquide company, is the nation's leading single-source supplier of gases, welding and safety products. Known locally nationwide, our distribution network serves more than one million customers of all sizes with a broad offering of top-quality products and unmatched expertise.