Seam Welding Machines

Seam Welding, An Overview

One of the most widely used welding techniques for creating an airtight and watertight seal is seam welding.  The seam welding process can be done using GMAW, GTAW or Resistance Welding.  Today we’re going to be sharing some basic information about this high-quality welding option as well as insights about how automation can improve your team’s seam welding process—let’s dive into it!


What is Seam Welding?

The process of joining workpieces made of similar or dissimilar materials along a continuous seam is known as seam welding. One of the biggest benefits to seam welding is that the materials can be similar or dissimilar. Seam welding comes in three forms:

  • Traditional Seam Welding: Overlapping weld nuggets using GTAW or GMAW process.
  • Friction Seam Welding: A continuous weld is completed with heat generated by creating friction rather than with electrodes.
  • Resistance Seam Welding: Resistance seam welding is a technique in which the welding electrodes are motor-driven wheels.
GTAW Seam Weld
GTAW Seam Weld

Applications for Seam Welding

Within the world of welding, seam welding is one of the most preferred ways of using a continuous weld to join two different pieces of metal. Seam welding offers minimal distortion of heat and results in airtight and watertight seals with no gas formation. Because of these benefits (and more), seam welding has many common applications:

  • Barrel and exhaust systems
  • Pressure vessels
  • Steel drums
  • Radiators
  • Vehicle fuel tanks
  • Refrigerators
  • Oil transformers
  • Much more!

As if that weren’t already enough, there are even more production benefits to an automated seam welding process. An arc seam welding machine can be used for the mainstream manufacturing process, as it can produce high-quality welded seams with 100 percent penetration.

seam welding machine

Benefits of Automated Seam Welding

If you are looking for a consistent, high-quality seam weld that can increase your production speed without adding to your workforce, you will want to consider linear seam welders. The design of these automatic welder machines allows the weld seam to be clamped firmly between copper fingers and a copper backing bar. Some benefits you can expect from automating your seam welding include:

  • More efficient loading and unloading of seam welded parts
  • Ideal for a single pass, full penetration weld in cylinders, cones, boxes, and flat sheets
  • Simplifies the switch between seam welding different size parts
  • Our Seam welders can be equipped with TIG, Plasma, Submerged Arc, or MIG welding processes
  • All clamping fingers are equipped with reversible copper tips for maximum life.

At Bancroft Engineering, not only do we offer state of the art seam welding technology but also seam tracking systems. Seam tracking systems will allow you to optimize your welding to an even greater degree by aiding in extracting weld seam position. To learn more, visit our blog dedicated specifically to selecting the right seam tracking systems or contact us to speak with one of our welding specialists.

Seam Welding Machine

Looking to optimize your welding process with improved efficiency and a stronger end-product? Whether it’s with a seam welding machine or welding fixture and tooling, we’ve got you covered. Our team of engineers have experience designing completely customized automated welding systems or semi-automated solutions to fit your needs.

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TIG Seam Welder
TIG Seam Welder by Bancroft
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welding automation custom machine

Top 3 Ways Welding Automation Can Bridge the Skill Gap

Back in 2015, the Bureau of Labor Statistics (BLS) and the American Welding Society (AWS) were already projecting a shortage of greater than 291,000 skilled welders for the year 2020-2022. Yet we find ourselves here in that future and it’s just as competitive as ever. Why? Because there will always be a demand for skilled welders. Today we’re going to discuss three ways welding automation can help your company meet that demand in creative and effective ways.


What is the Welding Skill Gap?

A skill gap can occur in any industry. It happens when the demand for a specialized skill set, and the supply of experienced professionals do not match up. In welding, it means that the younger, inexperienced welders who are new to the trade simply don’t have the quality of work that their retiring, veteran welder counterparts have [yet].

We are seeing this gap grow in the fabrication industry for several reasons:

  • Lack of experienced master welders because many are near (or at) retirement age
  • Emphasis on 4-year degrees versus trade school causing students to reconsider entering the trades
  • Skilled tradespeople retiring before mentoring less experienced welders
  • New welders lacking hands-on experience

The frustration is felt by both the employers and the welders. That’s where welding automation comes in. Robotic and semi-automated welding solutions offer a practical, smart solution to bridge the gap between what your fabrication quality demands and what your team needs without waiting for new welders to reach a specific skill level.

1. ) Welding Automation Improves Safety

In 2019, the Bureau of Labor Statistics reported 6,030 total cases of nonfatal occupational injuries and illnesses involving days away from work among welding, soldering, and brazing workers. Many of these injuries may have been avoided with more training and better equipment.

Welding automation provides an extra measure of safety to your team in several ways:

  • Machines have built-in safety equipment to protect humans such as guarding, fences and sensors.
  • The process of automating reduces the possibility of spontaneous injuries through simple, streamlined programming.
  • Just a simple welding positioner can offer lightweight, easy-to-handle solutions to meet even the most demanding, repetitive welding jobs.

With automated welding, even the most inexperienced member on your team will advance his/her skill level. Automation programming protects them from making simple mistakes that often result in injury.

automated welding machine
Custom Welding Machinery

2.) Welding Automation Increases Efficiency

Welding automation takes human error out of the equation, which helps improve safety as well as increase efficiency and quality. When programmed by a skilled welder, these machines can effectively multiply that skilled welder’s work. It’s essentially like cloning your best welder’s skill set and applying that ability to any team member. Imagine the effect this would have on your productivity!


3.) Welding Automation Ensures Quality

Part of the process of building high-quality welding systems includes rigorous testing at many phases of the design process. Bancroft’s full-service staff will provide installation, training, preventive maintenance, and production process improvements to make sure your robotic welding system solution is a success. This will ensure a high-quality weld no matter the welder’s skill level.

Automated welding Positioner
Bancroft's Automated Welding Positioner

Automated Welding

Bancroft’s expertise & technology can help you bridge the welding skill gap and improve your operations. Our options range from simple, stand-alone machines to full robotic welding automation systems. We specialize in semi-automated welding machines for rotary welding, TIG/MIG welding, spot welding, resistance welding, laser welding and much more!

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Limiting Weld Cracks with Custom Welding Systems

Welding cracks are one of the more severe defects.  If you have a weld cracking problem, there are two questions to ask yourself to address the root of the problem:

  1. Did the crack occur during the weld, after cooling or during a secondary/finishing operation?
  2. Is the crack located within the weld or next to it?

Our custom automatic welding machines help limit weld cracks and achieve high-quality results. Let’s walk through a few common types of weld cracks and what you can do to limit them in the future!

Centerline Cracks

Commonly referred to as longitudinal cracks, centerline cracks typically extend the entire length of a weld. This happens when one or more of the following occur: there is an improper width-to-depth ratio, you’re using a base material with a low melting point or when the welding surface is concave in shape.

How to Limit Centerline Cracks

  • Run a lower current to decrease penetration
  • Decrease voltage
  • Slow down travel speeds
  • Aim for a width-depth ratio between 1:1 – 1:3:1
centerline weld crack
Example of a Centerline Crack

Crater Cracks

When the weld pool doesn’t have enough volume after the cooling process, crater cracks occur. This is most common when welding aluminum as it’s susceptible to both heat and stress cracking during the welding process. Stainless and carbon steels are much less susceptible to crater cracks, but caution must still be taken!

How to Limit Crater Cracks

  • Ensure your using enough filler material
  • Check that your parts have the proper fit up
  • At the end of your weld, weld back over the bead for 0.5-1 inch (overlay technique)
Crater Crack
Example of a Crater Crack

Root Cracks (Underbead or Toe Cracks)

This type of crack is located at the weld toe—or a heat affected zone. Underbead cracks occur at lower temperatures and sometimes are not discovered until 72 hours after the weld cools. This occurs when welding a sensitive material with excessive Hydrogen—which results in shrinkage, stresses, and cracks!

How to Limit Underbead Cracks

  • Reduce Hydrogen by rethinking your filler metal and check the storage environment of your filler metal
  • Apply thinner weld layers
  • Increase time between passes
  • Maintain proper pre-heat and post-heat protocol
Welding Root Cracks
Example of a Root Crack

Transverse Cracks

Similar to underbead cracks, transverse weld cracks also commonly are not noticed until after the weld cools. They share the same causes as underbead cracks—too much Hydrogen and shrinkage stress. Transverse cracks most often occur on high strength steels that don’t require pre-heat.

How to Limit Transverse Cracks

  • Reduce Hydrogen by rethinking your filler metal or check the storage of your filler metal
  • Maintain proper pre-heat and post-heat protocol
  • Use lower strength consumables
Transverse Cracks
Example of a Transverse Crack

Custom Welding Systems that Prevent Cracks

Our biggest piece of advice is to make sure you have everything in order before welding, as it’s much easier than trying to fix problems later down the road. Always follow basic guidelines for cleaning and storing your base and filler material and carefully select the right welding equipment!  Need more help? Reach out, we’re here for you!

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welding positioners 101

Welding Positioners 101 NEW Automated options

How often do you notice your welders working hunched over or welding above their heads? The welding position affects EVERYTHING about the end result. Without a reliable configuration, quality, productivity and safety all suffer. Cue the welding positioner.

We’ve put together this basic guide on welding positioners and run through the many options we have to not only improve your welding operation but make it a whole lot easier.


Weld Positioner Applications

Positioners can be applied to a diverse mixture of applications, but they are most commonly used for the rotation of parts during the welding or assembly process. They provide a consistent plane of rotation even bearing a significant amount of weight.

Weld positioners can be used for both manual welding, semi-automated welding or used to complement a robotic system. A few of the key industries currently utilizing weld positioners include:

  • Heavy construction or machine manufacturing
  • Military
  • Automotive
  • Aerospace
  • Steel & pipe industries

Standard vs Automated

The welding positioners designed by Bancroft Engineering can be custom configured to fit your needs. These innovative options allow the positioners to be even more flexible and satisfy the most stringent of customer demands. All of our standardized positioners can be fully customized with one or many of the following options:

  • Increased torque capacities
  • Digital displays
  • Hardware and special hole patterns for easy fixture mounting
  • On/off foot switches
  • Safety locking
  • Aluminum tables
  • Other customizations upon request
automated welding positioner

If it’s more control you are looking for in a welding positioner then our line of automated positioners could be your solution.  Designed with both the harsh welding environment and cost in mind, these automated positioners can be integrated into any power supply.  They are PLC controlled and available with:

  • Programmable rotation distance
  • Variable speed and direction
  • Rotary delay and craterfill timers
  • A repeatable tooling home location
  • Manual or pneumatic torch shuttle
  • Live center
  • Tilt and pivot options for better weld positioning

Watch our TT530 Automated Positioner in Action!

Welding in the Right Position

One of the main perks of welding positioners is that you’ll always be in the best position and angle to generate high-quality output. Positioners also save floor space, give the ability to manage higher load capacities in a safe way and decrease cycle times. Along with production benefits, positioners produce a quick return on investment!

Read more on what to know about welding positioners in this blog post.


Choosing the Best Welding Positioner – Our line of Premium Positioners

TT100 Rotary Positioner: Ideal for small weldments weighing up to 100 pounds. Capable of handling up to 300 amps of welding current.

welding positoners

TT210 Rotary Positioner: 200 lb. vertical load rating. Capable of handling up to 300 amps of welding current.

TT 210 positioner

TT500 Rotary Positioner: 500 lb. vertical load rating. Capable of handling up to 500 amps of welding current.

Welding Positioner

RT2000 Rotary Positioner: 2,000 lb. vertical load rating. Capable of handling up to 1,000 amps of welding current.

welding positioner

TT530 Automated Positioner:  500 lb. vertical load rating, 500 amps of welding current, programmable rotation distance and repeatable torch locating mechanism.

automated welding positoner

TT535 Automated Pivoting Positioner:  All the specs of a TT530 with the ability to pivot up to 90 degrees into a fully horizontal position.

automated welding positioner

Get the full list of specifications for our weld positioners right here.


Looking for a positioner from a trusted and authentic supplier? Bancroft Engineering is a leading provider of semi-automated welding equipment. We design and build weld positioners in a variety of different specifications and can help you meet any custom requirement.

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GMAW, MIG or Wire Welding Problems

Whether you have been welding for years or just getting started in your career, addressing and solving GMAW, MIG or wire welding defects can be extremely frustrating. The team at Bancroft Engineering is here to empower you to take your GMAW / MIG / wire welding operation to the next level. Read on to learn about common wire welding problems and tips for achieving high-quality welds.

Basics of GMAW Welding

GMAW welding, commonly known as MIG welding or wire welding, utilizes a semi-automated welding system.  The process uses a solid wire—or flux core wire vs a long “stick” electrode. During this process, an electric arc forms between the wire electrode and the metal—the emerging heat causes the metal to join and melt.

Common Wire Welding Defects

While many weld defects are usually easily spotted, some won’t show up until your part goes through the quality assurance process. It’s also worth noting that just because a weld doesn’t look “good” to the eye, doesn’t mean it’s bad!  The following are the most common MIG welding problems:

  • Pinholes
  • Porosity issues
  • Too much weld deposit
  • Improper weld penetration
  • Lake of fusion
  • Cracking
  • Spatter
  • Lack of uniformity
  • Discoloration
pinholes-MiG welding
Example of Pinholes
porosity issue-MIG welding
Example of Porosity Issue
example of cracked weld-MIG welding
Example of Cracked Weld
example of welding spatter-MIG welding
Example of Welding Spatter

Check out our article dedicated to enhancing welding quality with more tips here.


Conditions Creating Poor MIG Welds?

Some of the most likely reasons your MIG process is resulting in poor quality welds is one or a combination of the following:

  • Impurities or improper cleaning
  • Skipping pre- or post-heat processes
  • Using the wrong filler metal
  • Using the wrong shielding gas
  • Running the wire at the wrong speed
  • Using too little (or too much) voltage
  • Skipping joint preparation steps
  • Improper welding techniques/setup

Other things to check are part fit up or damaged equipment (cables, clamps, etc.).


Tackling Quality Assurance / Quality Control

QA/QC plays a critical role in ensuring reliable welds are produced with minimal rework. The best way to catch defects is to incorporate quality testing throughout the welding process to confirm your weld meets the needed specifications. This will ensure that issues are caught early on, allowing for adjustments to be made and preventing further defective output.

Choosing the Right Equipment

Utilizing the right equipment will make or break your welding output! A high-quality welding equipment builder will help recommend parameters for your welding needs. They can also walk you through the proper wire feed speed, amperage, voltage and compatible shielding gas. The experienced team of semi-automated MIG welding system builders at Bancroft Engineering can help you get the proper welding equipment in place and running smoothly.

Custom Welding Systems

Automated MIG Welding System Builders

Like any skill, mastering MIG welding takes time and practice to gain the best results. We hope some of these simple tips will help you improve your process and achieve great results. Get in touch with our welding engineers today to learn how our automated and semi-automated equipment can help your business.

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best automation welding systems

Why Skilled Welders Make the Best Automation Programmers

Integrating welding automation into your manufacturing process has major benefits. Automated welders and robots are more efficient than humans and can improve overall productivity. BUT that doesn’t mean skilled welders are no longer useful—far from it.

Skilled welders have a wealth of experience and knowledge surrounding the welding process, making them some of the best automation programmers around. We’re diving into the 4 reasons why we think skilled welders make the best automation programmers—Read on!

#1. Welding Process Understanding

Producing high-quality welds requires process-specific knowledge. Manual or automated, the understanding of how the process works is vital! The most common variables include:

  • Part variability
  • Welding torch position
  • Heat input
  • Travel speed

Leveraging a skilled welder’s expertise can greatly reduce the time and effort it takes to setup or improve automated welding systems and programs.

#2. Application & Equipment Insight

It’s commonplace for the operator to be involved in selecting the automatic welding equipment setup and variables. To properly configure a welding cell, it’s important to have the knowledge of the best equipment for the specific welding application. Take the GMAW process for example, the following must be selected correctly:

Tapping the knowledge of a seasoned welder during this decision-making process often results in higher weld quality, lower scrap, improved production rates, higher ROI’s and a better-optimized overall-setup.

#3. Troubleshooting & Optimization Knowledge

Troubleshooting and problem-solving skills is a requirement for any kind of welder. Veteran welders are well-versed in overcoming challenges such as part inconsistencies, reducing rework and achieving cosmetic requirements. A skilled welder will also be well versed in the limitations of a process, peripherals and material types.

#4. Ongoing Growth & Innovation

Automation has become possible for more than just large corporations. Technology is becoming more flexible, making automation systems economically justifiable and productive for manufacturers of all sizes.

We’ve seen a number of small, repetitive welding jobs be transitioned to an automated process, freeing up skilled welders for more difficult projects. This not only keeps your skilled welders learning and growing but also encourages them to continue to be challenged in their day-to-day job and move your business forward!

welding automation system types

Custom Welding System Builders

Automation is aimed at supplementing the welding workforce, not replacing it! Bancroft Engineering has the experience and equipment to help manage a transition to automated or semi-automated welding. Get in touch with our engineers today to discuss how we can help optimize your process with custom equipment.

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automated welding trends for 2021

5 Trends in Automated Welding for 2021

Automation in the welding industry has been a growing trend since the 70’s. There has been an increase in demand from end-user industries and market growth continues to be on the upswing. These demands have been supported by the continued advancements in technology and R&D surrounding both automation and welding.

As we move into the New Year, we thought it would be worthwhile to review 5 trends in automatic and semi-automatic welding from our perspective.

Trend #1: Welding Safety Enhancements

Safety should always be number 1!  While this is not a new trend, fabricators will continue to take steps to keep workers safe. Without the proper safety precautions, automated welding can be dangerous. Here are just a few of the most common hazards:

  • Exposure to Gases & Fumes
  • Physical Hazards such as burns, eye damage, cuts, etc..
  • Electric Shock
  • Fire & Explosions

To improve the safety surrounding automated welding, we’ve seen more and more adoption of interlocking perimeter guards, safety light curtains, laser scanners, sensors, pressure-sensitive safety mats, high-quality gear, auto doors, better smoke extraction systems and more!

Auto doors with safety enclosure

Trend #2: Labor Shortage Issues

There’s been a lot of discussion around the welder shortage in the United States—it’s estimated that there will be a deficiency of over 400,000 skilled welders by 2024. This is an extremely challenging hurdle for manufacturers looking to expand and fill demands. At Bancroft Engineering, we understand what an asset welders are to our economy and the importance of education for the younger generation.

Trend #3: Automation Technology Growth

New technology will continue to emerge as we move into 2021.  New tools and technologies that will see growth include:

  • Power Sources
  • Digital Control Systems
  • Welding Management Software
  • Seam Tracking Systems
  • Gas Control Devices
Seam Tracking System
Automated Welding Positioner Prototypes
Automated Welding Positioner Prototypes

The team at Bancroft Engineering has been hard at work implementing new technology for all of our customized and standard semi-automated welding equipment. Stay tuned for the release of a new automated welding positioner and seam tracking systems coming later this year!

Trend #4: Rise of Collaborative Welding Systems

The welding industry will continue to embrace collaborative systems to compensate for the increasing skilled labor shortage in 2021. Collaborative welding systems are designed to share a workspace with humans—creating a safe and seamless automation environment.  This is one of the latest big trends in automated welding as it can be deployed easily, used for a variety of welding applications and are affordable compared to large robotic systems.


Trend #5: Adaptive Control Advancements

For those looking to improve their automated welding operation in 2021, adaptative controls are high on the list.  Adaptative control are used to analyze welding data in order to make corrections and improvements based on the results. These corrections are made automatically to the weld current—in real-time. This data is critical for improved quality and process optimization.


The Future of Automated Welding

With the use of new and improved welding technology, there are many opportunities to increase productivity and uncover time and cost savings. Technology advancements can help you address critical welding challenges which will allow you to stay competitive!  If you’re looking to adopt automated welding or make an upgrade, our team of trusted engineers are here to help you select the best equipment that will have the most impact on your business and bottom line.

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solve wire feed problems when welding aluminum

How to Solve Wire Feed Problems When Welding Aluminum

Aluminum has gained popularity over the years for manufacturing parts both large and small. It’s lightweight, strong, highly corrosion resistant, has good electrical and thermal conductivity and is reflective to both heat and light. While aluminum is a common material used by fabricators, it can be rather frustrating to weld—mainly due to problems with wire feeding.

We have seen every type of wire feed challenge with both manual and automatic welding—from unstable arcs, birdsnesting, burnback and everything in between. Read on to learn more about how you can minimize issues associated with aluminum wire feeding, avoid downtime, and improve your welding output!


Why is Welding Aluminum Difficult?

Welding aluminum requires different techniques than steel.  Different shielding gases, pre and post-welding processing, wire, and feed rolls. It is not only softer but has less column strength than steel which makes it more vulnerable to buckling and tangling.

Here are a few other properties of aluminum that make it difficult to weld:

  • High thermal conductivity
  • Low melting temperatures
  • Fast cooling rates
  • Oxidized surface coating

While it may seem that welding aluminum and dealing with welding wire problems is high maintenance, it’s easy to overcome with a few key steps!

How to Solve Poor Wire Feeding

In order to combat wire feed issues, it’s key to understand your welding equipment and components. It’s also essential to take a look at the way your equipment is configured.

1. The Welding Gun

The two best guns to use with aluminum are spool guns and push/pull guns.

  • A spool gun is best for small applications that doesn’t require much changeover. One way to minimize feed problems with spool guns is to shorten the feed distance.
  • A push/pull gun allows for longer wire feed distances (up to 50 feet). These guns are built with a motor that pulls the wire and a secondary motor that pushes the wire through the liner.
welding spool gun
Welding Spool Gun

2. Drive Rolls & Correct Wire Tension

To avoid crushing or deforming aluminum welding wire, use a U-groove drive roll. These drive rolls keep a round shape while feeding the wire effortlessly.

Setting the drive roll tension can be tricky and often takes practice to get it right. To start, make sure your drive rolls are aligned. Use low pressure, but make sure it provides enough for consistent wire feeding. The point is to avoid stress on the wire while the system is feeding the wire to the contact tip. Stress on the wire will cause an unstable arc.

3. Type of Welding Wire

High-quality aluminum wire is a must to avoid feeding problems. Check that your wire has a smooth finish and a steady cast. If your using a poor-quality wire, it can result in a wavy motion leaving the contact tip which will cause an unstable arc.

4. Contact Tips & Other Consumables

Look for aluminum specific contact tips. These are designed with smooth bores that have larger diameters for feeding wire. Since aluminum expands when it’s heated, these tips allow for wire to flow and prevent burnback.

The two specific liners that should be used for welding aluminum are Nylon and Teflon. These prevent birdnests and increase the life of your contact tip.

Aluminum wire birdsnest
Aluminum Wire Birdsnest

5. Handling Approach

Following spool handling best practices is another way to limit wire feeding issues. Here are a few handling strategies to keep in mind:

  • Always lift the spool from either the center or the bottom.
  • Don’t lift the spool in a way that permits the flanges to angle away from the wire.
  • Don’t adjust or disturb the way the wire is wound on the spool.


Custom Welding Machine Builders

Bancroft Engineering has the experience and equipment to help manage your aluminum welding woes! Get in touch with our engineers today to discuss how we can help optimize your process with custom welding machines.

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welding power supplies

Types of Welding Process and Power Supplies

Photo Above: MIG Welding Process

The primary function of a welding power source is to convert electrical power into a current type that is suitable for the welding application being performed.  There’s a lot to consider when selecting the best power source for your welding systems.

Whether you’re looking to invest in new manual welding machines or ready to upgrade an outdated welder to a more modern piece of automatic welding equipment, we’re here to simplify the process. Read on to learn more about welding power sources and what key factors to consider before making a purchase.


Getting Started

There are a variety of power sources to choose from. To make the best choice, you need to pair your material type with the welding process and the best method of supplying power to the arc.

Choose your Welding Process 

Both the welding process and material type play a big role when selecting a power source because they are not always compatible with each other.

Gas Metal Arc Welding (GMAW) or Flux-Core Arc Welding (FCAW)

Most commonly referred to as MIG or Flux-Core Welding; this process can be used on all of the major commercial metals, a wide range of thicknesses, and requires less operator skill than TIG or stick welding.  Welding speeds are higher because of the continuously fed electrode, absence of slag, and higher metal deposition rates.  Whenever possible, GMAW and FCAW are the chosen welding processes utilized in production shops.

Shielded Metal Arc Welding or Stick Welding (SMAW)

This is the most common form or ARC Welding.  A stick or electrode is placed at the end of a holder and an arc is struck between the tip of the electrode and the metal welding surface.  SMAW power supplies are generally the least expensive but are only capable of being used in manual operations.

Gas Tungsten Arc Welding (GTAW)

In GTAW—or TIG welding—an arc is established between a non-consumable tungsten electrode and the base metal.  A shielding gas protects the tungsten and molten metal from oxidation.  GTAW produces high-quality welds on almost all metals and alloys.  It can be controlled down to very low amperages making it ideal for thinner materials.  GTAW can be done with or without filler material, it also has very little spatter and no slag.  Its biggest disadvantage is speed—GTAW is by far the slowest welding process.

TIG welding process
Tig Welding Process

Plasma Arc Welding (PAW)

Plasma Arc Welding is essentially an extension of GTAW.  Both GTAW and PAW use constant-current power sources and a high-frequency source for arc starting.  The primary difference is that the electrode is recessed in a nozzle to constrict the arc.  PAW is generally more expensive than GTAW but it is more tolerant of joint misalignment and can give better penetration.

welding power sources
PAW Welding Process

Submerged Arc Welding (SAW)

In a SAW welding process, the wire is fed continuously with a granular flux material to cover the weld area.  The flux plays a key role in achieving high speed and a quality weld.  Very little weld fume is produced— eliminating the need for fume extraction.  Utilizing granular flux limits welding positions and requires special handling and recovery solutions.

SAW welding process
SAW Welding Process

Select the Proper Power Supply 

Welding power source types are defined by how they modulate electrical currents and what arc welding process is best supported by this modulation:

Direct Current (DC)

A DC power source is a flow of electrons in a single direction through a circuit. In welding, it creates a steadier arc and smoother output. It can be used to weld with a negative ground, or the flow of electrons can be reversed to flow toward a positive ground in reverse polarity.

Alternating Current (AC)

The AC power source is the bidirectional flow of electrons in which the polarity shifts a hundred or more times per second from a negative to a positive ground. Arcs tend to be less stable and welding is harder to control. However, AC welding can break apart oxide formation and allow for purer welding in some processes.

Pulsed Current

This is a form of DC welding in which the current goes from a high peak current to a lower background current at a frequency determined by the operator. This narrows the arc, allowing greater penetration while reducing the effect on surrounding materials. As a result, pulsed current welding is an excellent choice for welding thin metal or performing deep welds on thicker materials.

Pulsed Voltage and Heat

Pulsing GMAW power supplies focus on controlling pulsed voltage and heat applied to the consumable electrode. Controlling the pulsed voltage (heat) and wire feed speed allows greater control over how the wire melts and the rate of deposition. Adaptive pulse GMAW carefully monitors feedback and automatically compensates to keep the arc consistent despite variation by the welder and differences in height and joint location.


Additional Items to Consider

Once you have your welding process and the type of power source selected you should consider a few more key items to determine the size including:

What is your Input Power?

Your power source needs to match the type of input power available. The amount of electricity your welding system needs will ultimately depend on the type of power supply you select.

  • Single-phase: 115, 200 or 230 VAC
  • Three-phase: 230, 460 or 575 VAC

Material Thickness

Simply put, the thicker the material the more power required.

Duty Cycle

Duty cycle is the percentage of arc on-time a welding power source can operate in a given period. One of the most common mistakes welders make is under-sizing their power source. It’s important to understand how much amperage your power source can generate at any given duty cycle and ensure it’s MORE than enough to meet your demands.

Understanding the types of welding processes and power supply types is a large undertaking and can be overwhelming but a reliable power source will serve you for many years.


About Bancroft Engineering

Our engineers can help you select the best power source for your welding needs! Bancroft offers custom welding systems and a variety of standardized semi-automatic welding equipment in stock such as positioners, Welda-Round rotary welders, seam welders, weld-lathes and much more!

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Shielding Gas Types for GMAW

How to Choose Shielding Gas Types for GMAW

Welding Enhancements


If you’ve ever experienced a low-quality weld due to your shielding gas selection, this article was made for you. Shielding gas protects the hot weld pool from outside contamination, which is the main reason why it’s so important to make the right selection for your application.

Here at Bancroft Engineering, we’ve seen how much the wrong shielding gas can drop quality, increase costs and negatively affect production rates. We are going to dive into choosing the gas that’s best paired for your gas metal arc welding (GMAW) job so you can enhance your process once and for all. Whether you’re using a manual process, semi-automatic welder or fully-automated equipment, we’ve got you covered—read on!

About Shielding Gas Options for GMAW

Use one—or combine—these most common shielding gas options for GMAW:

Pure Gases

  • Argon is most commonly used for GMAW on nonferrous metals. This single-atom gas has a low thermal conductivity and ionization potential which results in a low transfer of heat to the exterior of the arc. Because of this, Argon delivers a deep yet narrow weld penetration.


  • Helium has lower density than Argon which requires higher flow rates. Helium is also a single-atom gas, that’s commonly used on thicker materials. It’s also a good choice for welding aluminum. Because if its limited high price though, Helium is seldom seen in the industry anymore.


  • Carbon Dioxide (CO2) is rarely used on its own because it yields a wide weld bead and often ends up producing a lot of spatter. CO2 is more commonly combined with Argon to produce the best end result. CO2 is also a reactive gas, meaning it has high ionization potential.


Gases Used in Mixtures

  • Oxygen is a two-atom molecule commonly added in GTAW gas mixes at a rate of 10% or less. It may be seen as an addition to Argon for GMAW as it can help create a deep and narrow weld penetration in specialized applications.


  • Hydrogen is an active shielding gas also commonly used in GMAW mixes at a rate of 10% or less. This diatomic molecule tends to result in hot and wide surface beads. Hydrogen is mostly used for stainless steel materials to improve fluidity and increase travel speeds.


How to Select a Shielding Gas 

There are three main components to consider when selecting shielding gas for GMAW: material type, filler type and transfer mode.

  • Material Type: The most important factor of all is matching your gas to the material type. For instance, steel is much denser than aluminum which requires different shielding gas to achieve a desirable welding outcome. It’s also important to consider the materials thickness as thicker materials will require higher heat inputs.


  • Filler Metal Type: Double check that your filler metal matches the base material. This will give you reassurance when it comes to selecting the best shielding gas.


  • Welding Transfer Mode: Determine whether you’re using short-circuit, spray-arc, pulsed-arc or a global transfer. Each transfer mode will play better with certain shielding gases than others.


There’s a lot more to cover when it comes to shielding gas for GMAW. Stay tuned for future articles where we’ll walk through proper shielding gas flow and we’ll dive into detail about the GMAW process with each material type!


GMAW Welding Equipment Builders

Selecting the right shielding gas is an important step towards welding success. When optimized correctly, it will not only improve your weld quality, but also save you money and time. The team at Bancroft Engineering can help you decide on the proper shielding gas and ensure your automated or semi-automated welding system is producing the very best results. Get in touch with our welding engineers today!

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