What Does a Good Weld Bead Look Like? A Guide to Quality Welding

Producing a weld bead and joining two metal pieces is a skill that can be learned with practice. However, the key to becoming a professional welder is not just the act of welding but understanding the quality of the weld. This understanding is what sets professional welders apart from hobbyists.

Although the appearance of a weld bead can tell you a lot about the weld and the welder's experience, its quality and strength run much deeper. Many beginners and new welders wonder what a good weld bead looks like and what makes it different from a poor one.

In this article, we will provide a comprehensive guide to quality welding. We will explain the differences between good and bad weld beads, and you will have a thorough understanding of what makes a good weld and how to achieve it.

Good Welds vs. Bad Welds
Source: https://www.youtube.com/watch?v=kwnlcohZUZM

What Is A Weld Bead?

A weld bead or weld is a product of molten filler metal or electrode that fills the gap between two pieces. If the process doesn't use a filler metal (autogenous welding), a weld is made of the molten edges of two pieces.

Diagram of a Weld Bead
Source: https://www.wcwelding.com/parts-of-a-weld.html

As you weld, the heat of an arc melts the edges and filler metal. Molten filler metal creates a weld puddle or pool that penetrates the joint. Once the weld puddle solidifies, it forms a weld bead or a weld.

Welding creates complex decorative and load-bearing shapes and structures between two pieces. Various factors can affect the appearance of the welds, with the most common being voltage, amperage, welding technique, filler metal choice, and shielding gas.

However, in addition to looking good, the welds must penetrate the pieces and hold the structure together. Therefore, producing high-quality welds is more than just making them look pretty.

Producing high-quality welds goes beyond appearance.
Photo by @welding_art (TikTok)

What Distinguishes Good from a Bad Weld?

There are several factors you'll need to take into consideration to tell the difference between good and bad welds. Most importantly, you should evaluate the following:

• Weld aesthetics: A first look at the weld can tell you so much about it. You can immediately see whether it is uniform, consistent, colorless, or without holes or cracks. In some industries, aesthetics are paramount, so it won't be hard for you to differentiate a good from a bad weld just by looking at it.

Visual inspection allows a preliminary weld quality assessment.
Source: https://blog.daihen-usa.com/why-welding-parameters-are-so-important-to-finished-quality

• Weld size and shape: A good weld is straight, neither too large nor too small for the joint. It should adequately fill the joint without undercutting one side or overflowing the gap. The weld's shape can also help you tell a good weld from a bad weld.

• Weld defects: Many weld defects, such as porosity, cracks, undercutting, or excessive reinforcement, form on the weld's surface. Seeing holes or cracks on your welds is never a sign of good and high-quality welds. However, weld defects can be subtle and run deep inside the welds.

Source: https://weldingofwelders.com/welding-defects-and-their-types/

Although a first glance at a weld can tell you a lot about it, visual inspection is often not enough to determine its quality. Weld defects, such as lack of penetration or fusion, internal porosity, slag inclusions, or cracks, occur inside the welds.

You can create beautiful and uniform welds that sit on top of the joint rather than penetrate the pieces. To check the structural integrity of the weld, you will need testing methods such as X-ray inspection, ultrasonic testing, liquid penetrant testing, or magnetic particle testing.

NDT (Non-Destructive Testing) in Weld Quality Inspection
Source: https://oil-test.dz/non-destructive-testing-ndt-inspections/

Characteristics of Good Weld

To answer how you recognize a good weld bead, you will need to look for crucial characteristics. Here is a checklist of attributes of a good weld bead:

Image of a Good Weld. A smooth, uniform weld free from undercutting, overfill, and spatter.
Source: https://www.mig-welding.co.uk/forum/threads/welding-stainless-and-making-it-look-good.39599/

Signs of a Bad Weld

To understand the difference, we will also explain the characteristics of a bad weld. Here are crucial signs of bed welds:

How To Produce a Good Weld Bead: A Guide to Quality Welding

Understanding the difference between a good and a poor weld is the first step in quality welding. Knowing something is wrong with your weld is essential, but you should also learn how to address the issue.

In this section of the article, we will present tips on producing a good weld using the three most popular arc welding methods: MIG, TIG, and Stick welding.

Source: https://bakersgas.com/blogs/welding-tips/how-to-start-welding

How To Get a Good MIG Weld

MIG welding (Gas Metal Arc Welding) is quite a straightforward and beginner-friendly method. Its semi-automated principle and forgiving arc are excellent for beginners and new welders just getting into the trade.

However, several things are needed to produce sound, high-quality MIG welds. Here is a quick guide on how to create good MIG welds every time.

MIG Welding Process
Photo by @weldsbyzen (TikTok)

Step 1: Gather the equipment.

Use a reliable MIG welder with a consistent power output to produce a stable arc. A stable arc is crucial in creating uniform and consistent welds. Make sure the MIG wire type fits the base metal and that the size is suitable for the thickness of the metal. A good MIG wire choice will produce sound and properly sized welds.

Ensure your welder has enough power for the material you are welding. MIG welders rated at 200 amps, such as the YesWelder MIG205 DS , will cover most of your home and hobby welding needs. Enough power is crucial for melting the base metals and filler wire.

MIG-205DS-Pro Multi-Process MIG Aluminum Welder

Step 2: Clean and prepare the pieces

Clean surfaces yield clean welding results. To achieve the best weld appearance, clean all dirt, rust, oil, or other contaminants from the surface. Clean surfaces reduce the risk of porosity in MIG welding.

Clamp and fit up the pieces. Securing the pieces and providing an even groove across the joint is crucial in producing uniform welds with consistent width and size.

Source: https://www.youtube.com/watch?v=gmy1VcFmH28

Step 3: Set up the welding parameters

Make sure your wire feed speed (amperage) and voltage are suitable for the thickness of the metal you are welding. Using enough heat is crucial for melting the pieces and filler metal, resulting in proper penetration and fusion.

To set up the parameters, check the manufacturer's recommendations and instructions. Alternatively, you can use a welder with smart settings or synergic MIG, such as the YesWelder DP200 Dual Pulse Welder . The welder will adapt WFS and voltage based on material size, wire size, and type to give you a head start. If you notice you are running a bit too hot or cold, you can constantly manually adjust the heat. Additionally, you can use pulsing or dual pulsing with it to produce TIG-like welds on aluminum, improving the overall weld aesthetics.

Firstess DP200-KS Multi-Process DualPulse™ MIG Welder

Step 4: Check the shielding gas

MIG welding uses a solid or bare wire that requires external shielding. Shielding gases protect a molten weld puddle from reacting with atmospheric gases and contaminating the welds. Porosity and colors are the leading signs of contamination, whether caused by poor shielding gas or dirty surfaces.

Most welders prefer a 75% argon and 25% CO2 mixture when MIG welding mild steel. This mixture produces good arc stability and enough penetration to eliminate various defects. MIG welding aluminum, on the other hand, requires pure argon, while stainless steel uses two or a tri-gas mixture.

Shielding Gas Recommendation for MIG Welding
Source: https://weldguru.com/best-gas-for-mig-welding/

Step 5: Practice the technique

The welding technique, which includes factors such as travel speed, travel angle, working angle, arc length, and torch manipulation, is crucial. Each factor can significantly impact the quality and appearance of the weld. Therefore, it's essential to pay close attention to your technique when welding.

MIG Welding Technique
Source: https://weldingofwelders.com/welding-speed-and-travel-angle/

To produce consistent results and smooth and uniform welds, make sure you consistently move across the joint. Running too fast or too slow will cause various defects, including a lack of penetration or fusion, excessive reinforcement, overwelding, or a burn-through.

With MIG welding, you should use straight or stringer beads. On medium-thick pieces, there is no need for side-to-side motion. You just need to provide enough material for a good tie-in and to avoid undercutting.

Use Straight or Stringer Beads when MIG Welding
Source: https://www.youtube.com/watch?v=V7O5H--VlOg

How to Produce a Good Stick Weld

Stick welding is one of the oldest arc welding methods. Its low costs and ability to work outdoors on dirty or rusty pieces make it ideal for various industries and field repairs.

Shielded Metal Arc Welding (SMAW) is a manual method, so producing a good stick weld can be more challenging compared to MIG welding. However, here are some tips that can help you get satisfying results.

Stick Welding Process
Photo by @the_weld_life (IG)

Step 1: Get a reliable power source

Stick welders are small and simple machines that convert outlet power into welding power. To produce consistent results and uniform stick welds, you will need a reliable power source.

Features such as arc force or hot start can help you get a reliable start and battle voltage fluctuations that can produce uneven welds. These features are available in most new inverter stick welders, such as YesWelder Arc 205DS Pro . Although optional, these can help you yield even, smooth, and uniform welds.

ARC-205DS-PRO 110V/220V Stick& Lift TIG In One Stick Welder

Step 2: Choose the right Stick electrode for the job

Stick welding uses self-shielded electrodes or rods covered by a layer of flux. The flux protects the molten puddle from contamination, so external shielding is not needed.

Stick electrodes come in various types and sizes. The right one will depend on the metal type, thickness, welding position, specification and service conditions, and environmental job conditions.

For beginners, we recommend a 6013 rod in 3/32 "or 1/8" sizes. These are beginner-friendly and arc-forgiving electrodes that will help you produce good stick welds. Alternatively, you can consider E7018, one of the most commonly used rods. E7024 can produce pleasing weld aesthetics, while E6010 burns through contamination. However, it can be the trickiest to use and control.

Stick Welding with E6013 Electrode
Photo by @awesomewelding6 (TikTok)

Step 3: Adjust the amperage and prepare pieces

Setting up a Stick welder is relatively straightforward. You will need to adjust the amperage based on the metal thickness and electrode size. Each manufacturer has amperage recommendations, so follow the guidelines.

Providing enough amperage is crucial in producing enough penetration and good fusion. The heat should be sufficient to melt the electrode and base pieces. Running cold will cause penetration issues while running too hot will cause burn-through or excessive spatter.

Although Stick welding can burn through light surface contamination, it is always better to clean pieces before welding. Deep-penetrating electrodes burn away dirt, rust, and oils, but some can get trapped and cause porosity. That's why it is always better to clean the pieces and ensure a good fit to get consistent results.

Stick welding with deep-penetrating electrodes removes contaminants but may cause porosity.
Source: https://www.youtube.com/watch?v=aSeiMj1JOSc&t=748s

Step 4: Drag and weave the torch

Welders usually use SMAW to join thick stock. Welding thick pieces includes creating a wide joint, so you have to weave the torch to fill it. Weaving involves moving from side to side in various patterns, such as a zigzag, triangles, V, upside-down V, ladder, circles, crescents, etc.

When weaving the torch, spend enough time on the sides of the joint. This will improve the sidewall fusion and avoid undercutting with Stick welding.

Stick welding is a flux process that produces a protective slag. To avoid slag inclusions, you should always drag or pull the torch rather than push it. Also, remember to remove the slag before each pass. The only time you should push the stick electrode is in vertical up (uphill) welding applications.

Drag the Torch in Stick Welding
Photo by @HandyWelder2.0 (YouTube Shorts)

How to Produce a Good TIG Weld

TIG (Gas Tungsten Arc Welding) is arguably the most complex and challenging method. However, it produces some of the highest-quality, cleanest welds.

Its quality makes it valuable in the most demanding industries, such as aerospace, nuclear, food and beverage, hygienic tool applications, pressure vessels, and more. You'll need more experience to produce sound and high-quality TIG welds, but here are some fundamental tips.

Credit @txbestbanger (IG)

Step 1: Get a good TIG welder

TIG welding often involves welding thin sheet metal, so your welder should provide stable and reliable arc starts at low amps. If you plan on occasionally TIG welding aluminum or non-ferrous metals, you'll need an AC-current welder, such as YesWelder TIG200P AC/DC .

TIG-205P-PRO Pulse TIG Welder Stick/DC TIG/Pulse TIG 3 In 1 TIG Welder

TIG welders, such as the TIG200P, provide advanced features that can help you control the process and achieve high-quality results. You can adjust starting amps, ramp-up, peak amps, ramp-down, end amps, pre- and post-flow, or pulsing.

These features will help you control the process and the heat, which is essential when TIG welding delicate and thin metals. Heat control reduces the risk of warping, distortion, and burn-through while providing good fusion and penetration.

Keep in mind that it will take some time for a beginner to master setting a TIG welder. However, the results in high-quality welds are more than rewarding.

High-quality TIG Welds Display
Photo by @tig_happens (IG)

Step 2: Cleanliness is crucial

TIG welding is all about cleanliness. As noted, clean equipment and surfaces produce clean results. Therefore, make sure the surfaces are squeaky clean before starting to weld. Even light contamination of aluminum or delicate metals can compromise its quality or corrosion resistance.

Also, check your equipment and shielding gas. Damage to the tungsten electrode can cause tungsten inclusions or an unstable arc, yielding unpredictable results. Dirty or rusty TIG rods can also contaminate the weld.

TIG welding requires high-purity, inert shielding gas protection. Unlike with MIG, you cannot use semi-reactive or reactive gases. Argon is non-reactive, meaning it won't react with tungsten or molten weld puddle. If you notice any porosity, check the shielding gas supply and hoses.

TIG Welding with 100% Argon

Step 3: Choose the right TIG rod

In most TIG welding applications, you will need the filler metal. Fillers come in the form of rods that you manually feed into the joint. Choosing the correct TIG rod is crucial in producing a good weld bead.

The composition of the TIG rod should match the base metal to provide proper fusion. The filler metal diameter should be about the same thickness as the base material. Larger rods require more heat, so you can produce cold welds. Conversely, smaller rods can "evaporate" before properly penetrating the pieces.

Choose the Right TIG Rod
Source: https://www.youtube.com/watch?v=vbXPcaEQTvg

Step 4: Practice dabbing and moving

TIG welding is a manual welding method, meaning you'll need to control the feed, travel angle, travel speed, working angle, and manipulation manually. Unlike other methods, TIG involves using both hands. You'll hold a TIG torch in one and a TIG rod in the other hand.

The process of feeding the TIG rod into the joint is often called "dab and move, or dabbing." To provide proper TIG rod feed, and thus penetration and fusion, you must catch a rhythm of melting the pieces with the arc and dabbing the rod inside a molten weld puddle.

Perfecting this technique takes time. But when paired with the correct travel angle and consistent travel speed, it yields high-quality results and prevents undercutting. Feeding the right amount of filler at the right time will achieve a uniform bead of proper proportions.

Dab and Move Technique in TIG Welding
Source: https://www.youtube.com/watch?v=48kNktW0VYQ&t=278s

Final Thoughts

Good welds are smooth, uniform, clean, and consistent throughout their length. You can spot a good weld immediately, as porosity, cracks, or undercutting are never good signs.

Understanding the fundamentals of your process is key to producing sound welds. Regardless of the process, you will need a reliable welding machine that produces a consistent output. Other factors include adjusting the technique, choosing the right equipment, and employing proper weld preparation.