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Welding Best Practices

January 2, 2023
Man exercising the best practices of welding by wearing a full body safety equipment.

Welding is a process that consists of different technologies and an equally diverse range of materials. The process you use and the metal being worked on will largely dictate the tools and steps involved.

Having said that, there is a set of ‘golden rules’ that can be safely applied to all welding applications. In this article, the experienced fabricators at VeriForm Inc. go over welding best practices that will maintain both efficiency and the quality of your output.

Common Welding Challenges in Fabrication Environments

Although materials with a carbon steel base are often used in welding applications, they aren’t the only ones. Stainless steel, aluminum, and even bronze and titanium are becoming more common in manufacturing and fabricating environments. When you run an enterprise that welds different materials, you’re often looking at investing in more welding equipment as well as adjusting the schedule to accommodate equipment changeover between applications.

Do’s and Don’ts of Welding

Welding solutions designed for different types of materials can help you gain flexibility and efficiency while making high-quality welds. These best practices can help ensure you always have the right equipment on hand and use it to its best advantage.

DO Wear Appropriate Clothing and Safety Gear

Maintaining compliance with safety regulations and personal protective equipment (PPE) requirements is essential. This includes wearing the following during welding operations:

  • A welding helmet to protect the worker’s face from sparks and the ultraviolet and infrared rays that the arc emits
  • Clothing that doesn’t have pockets or cuffs that could potentially catch sparks
  • Respiratory protection to keep the welding fumes at bay

DO Clean the Metal Surface

It’s important to properly prepare the metal before you weld it. This includes removing surface contaminants like dirt, paint, and rust and sanding away any cracks or uneven surfaces. In most cases, a simple going-over with a powered wire brush is sufficient, but be prepared to go further if needed.

Should it be impossible to clean an area before repairing it, don’t use an MIG welder on it. Instead, use a stick welder with a 6011 rod and go slowly so gas bubbles escape from molten welds before these impurities can be trapped.

DON’T Stick to Basic Feeders

Don’t limit yourself to basic options when selecting wire feeders. In welding operations where materials are frequently changed, wire feeders with more advanced technologies can save time and increase productivity.

Dual feeder systems eliminate the need for separate welding cells for different materials. Integrated systems that include the power source and feeder on a single MIG runner cart can save time during setup and make it easy to move the equipment from one cell to the next. Advanced wire feeders also allow welders to save different weld programs, making it easy to retrieve the correct parameters for specific applications. 

DO Integrate Pulsed MIG Welding

Welders can produce high-quality welds and reduce rework by choosing a feeder and power source with pulsed MIG capabilities. Compared to CV MIG welding, pulsed welding is much better for aluminum because it provides lower heat input and greater arc control, reducing problems like burning, distortion, and spatter. 

There are also advanced pulsed welding processes that help you produce a better-looking weld and bead profile: some versions even compensate for welder inexperience by supporting accurate travel speeds and correct distances between the contact tip and workpiece.

DO Incorporate User-Friendly Welding Technology

With materials like aluminum and stainless steel, it can be more difficult to set the correct welding parameters to support the desired bead profile and penetration. Consider welding technologies that make these parameters easier to attain. For example:

  • There are welding power sources that assist welders in setting proper parameters. When the welder enters the material type, thickness, and wire size, the machine will establish the parameters necessary to create a quality weld.
  • When welding aluminum, a power source with a crater and hot start provides better arc starting and stopping capabilities. 

DO Choose the Right Filler Materials

It is critical to select the right filler metal for the application and base material. As aluminum and stainless steel come in many types, make sure the filler metal matches the base metal’s mechanical and chemical properties.

DON’T Use the Same Liner and Consumables for Different Materials

Welding steel should not be done with the same liner and consumables that weld aluminum. Cross-contamination or wire feeding issues can result. The liner for carbon steel is usually steel, while the liner for aluminum is plastic or Teflon with tighter tolerances. For the base material, you also need to use the correct feed guides and drive rolls.

DO Use the Appropriate Angle, Arc Spacing, and Speed

The correct angle will depend on the technology you are using. When wire welding, tilt the gun 10° to 15° in the direction you are pushing the weld. Maintain a 20° to 30° lead angle when stick welding.

When it comes to arc spacing, you’ll want to adjust your travel speed so that the arc remains within the leading third of the weld pool. With wire welding, maintain a distance of ⅜ to ½ inch. Stick welding requires a distance of 1/8” between the rod tip and the workpiece.

With travel speed, you’ll know that you’re going too slow when you’re producing convex, wide beads that have shallow penetration while depositing too much metal. If the travel speed is too high, the weld will produce a narrow, highly crowned bead. For most joints, the travel speed is well below 40” per minute.

VeriForm Inc.: Your Welding and Fabrication Experts

When you’re required to weld different materials, how well you adopt welding best practices can make a difference in your success rate. Pulsed MIG and advanced wire feeders allow operators to save time in setup and to produce high-quality welds, so investing in these additional capabilities can have a significant impact on the bottom line.

At VeriForm Inc., our CWB CSA W47.1 and W59 certified welders continually use welding best practices to ensure that we always meet your project specifications. We believe that in order to complete superior-quality welding, we need to use the best equipment and recommended technologies. To learn more about our metal fabrication services, please visit our website, call 519-653-6000 or contact us online.

Machining vs. Fabrication: Which is Better?

December 20, 2022

Machining and fabrication are two processes commonly used to create metal parts and components. Although a lot of machine shops and manufacturing facilities employ them to achieve comparable results, they are not the same.

At VeriForm Inc. we use both technologies to deliver client metalworking projects. In this article, we’ll go over the main differences between machining and fabrication and which one you should use for a given application.

What is Machining?

The metal machining process involves removing material from raw metals to make finished products or components. To achieve the desired shape, metal is cut, turned, drilled, or milled using a variety of machines, such as CNC machines. Our new CNC machining centre is long enough to duplicate multiple workstations, ensuring peak productivity and uptime.

Common machining technologies are highlighted in detail below.

CNC Milling

The CNC milling process, which is also known as 3D milling, involves moving the computer-directed tool across the workpiece simultaneously in three axes or more. With these machines, you can contour surfaces and drill holes with extreme precision. As a result, they are indispensable tools in the manufacturing industry.

CNC Drilling

Drilling takes place by rotating either the drill or the workpiece and feeding the drill along its axis into the workpiece. A computer-based drilling system is particularly useful for the mass production of components. With advanced and versatile CNC centres, drilling functions can be performed more quickly and on a repeatable basis.

CNC Countersinking

In countersinking, a V-shaped edge is created near the surface of the hole. It is often used for deburring holes or for making countersunk-head screws sit flush with surfaces. CNC milling commonly uses chamfering endmills to make countersinks.

Threading

Metal threading is a metal processing technique that involves making continuous helical threads on the surface of a workpiece. There are various applications for metal threading, including screws, bolts, and lead screw drives, which require high load capacity and precision in load transformation. 

Different threading technologies include:

  • Thread Cutting: Using tools and dies, thread cutting generates threads on the internal or external surfaces of cylinders and cones. By using a pattern-specific tool, this process removes excess material with each successive pass to achieve desired thread depth.
  • Thread Milling: During thread milling, the material is removed from the workpiece’s surface with a rotating milling cutter to create threads. The internal threads are carved out by inserting a milling tool into a hole and rotating it in a circular motion. A milling tool is fed to the outer surface of the workpiece to carve out external threads.
  • Tapping and Threading: In this process, threads are formed through the use of taps and dies. Taps are used to cut or form threads on the internal surface, whereas dies are used to cut threads on the external surface. 

Boring

Metal boring cuts a small amount of metal from a workpiece’s inside diameter to increase the accuracy and size of a hole. The process involves rotating either the boring tool or the workpiece and slowly feeding the former along the axis of the latter.

What is Metal Fabrication?

In fabrication, raw materials such as sheet metal, textiles, and plastic are used to create objects and parts. Specifically, the machine fabrication process involves the use of certain techniques to add, remove, cast, join, or form material. The highly trained members of our parts fabrication team use the highest quality precision equipment to cut, bend and assemble complex parts of any size.

Bending

By using a brake, a sheet metal company can bend sheet metal into shapes, and channels at angles up to 120 degrees. The thinner the gauge of sheet metal, the easier it is to bend. The opposite is also possible: sheet metal manufacturers can decamber strip-shaped pieces of sheet metal to remove the horizontal bend.

Cutting

Various pieces of machinery are available for cutting sheet metal, some of which are unique to sheet metal fabrication.

  • Laser Cutting: Laser cutters use powerful laser beams intensified by lenses or mirrors. They work well on thin and medium gauge sheet metal but may have trouble penetrating harder materials.
  • Water Jet Cutting: This method of sheet metal fabrication uses a high-pressure stream of water (mixed with an abrasive substance) to cut through the material. Since water jet cutters do not generate heat, they are often used to fabricate parts with low melting points.
  • Plasma Cutting: By creating an electrical channel of ionized gas, plasma cutters form a jet of hot plasma that can easily penetrate thick-gauge sheet metal. Although not as accurate as laser or water jet cutting machines, they are fast, powerful, and require little setup time.

Punching

When the sheet metal is placed between the two machine components, the punch forces itself through the metal to reach the die, creating holes. Punching removes circular pieces of materials, which can either be scrapped or turned into new workpieces- a process known as blanking.

Welding

With welding, heat is applied to a section of metal where it connects to another component, allowing both to be joined together. As the metal melts between the two components, it fuses to form a solid connection. Metals such as stainless steel and aluminum are comparatively easy to weld while others may require a specific welding process, such as arc, electron beam, etc. 

Some metal fabricators, including Veriform Inc., also offer powder coating and assembly services for completed components.

As soon as your part is fabricated, it will need machining to knock off the rough edges or maybe a hole will need to be drilled to add a metal component. It is common for something to be machined after it has been fabricated. An example of this would be to add metal objects to a plastic part or remove flash around the edges. 

VeriForm Inc.: Your Machining and Fabrication Experts

Machining and fabrication are key technologies when you’re working with sheets of metal. At VeriForm Inc., we have dedicated processes for aluminum, carbon steel, and stainless steel fabrication as well as CNC countersinking, drilling, laser cutting, and tapping. Our in-house personnel efficiencies will prepare and ship your machined and fabricated final products so you’ll have them when needed. To learn more, please visit our website, call 519-653-6000 or contact us online.

3 Best Methods of Welding Sheet Metal

December 5, 2022
TIG welder with welding gloves is holding welding torch of a welding machine and welding sheet metal.

When you’re working with sheet metal, the welding procedure you choose can determine the success of your project. If you don’t use enough heat, the weld penetration will be subpar and you can get brittle joints. Too much heat and you risk burnout. 

At VeriForm, Inc. we handle sheet metal using the latest and most advanced versions of proven welding technologies. In this article, we go over the 3 best methods of welding sheet metal, along with recommended applications for each one.

Gas Tungsten Arc Welding

Gas tungsten arc welding (GTAW), or TIG welding, uses tungsten electrodes that cannot be consumed. The tungsten electrode generates an arc that provides heat for welding. Filler material is often used to reinforce and build up welds. As with MIG welding, which will be discussed in the next section, a gas shield protects the pool from contaminants.

Depending on the filler size and how the filler wire is applied, TIG speeds range from 7” to 15” per minute. This method is not normally used on carbon steels due to its comparatively slower speed. However, it may be applied if the size of your MIG gun prevents you from accessing the weld.

  • Stainless Steel: Because of its clean appearance, TIG is primarily used on stainless steel. It is important to control heat input and speed when TIG welding stainless steel because it is prone to warping when heated unevenly. Unless the adjoining material requires brushing after the weld, there is usually no post-weld cleanup.
  • Aluminum: For many years, TIG has been the standard process for working with aluminum. For thicker materials, a preheat cycle may be required to ensure complete penetration of the weld. Filler metal is used in the weld puddle, so the speed is generally slower than MIG.

Gas Metal Arc Welding

Gas metal arc welding (GMAW), also known as MIG welding, uses a continuous solid wire electrode fed through a welding gun. When the contact tip is electrically charged, it melts the wire and creates a weld pool between the two components. A shielding gas protects the pool from environmental contaminants that could cause defects. Due to the spatter that is created during welding, MIG is best used for projects in which cosmetics and weld appearance are not important.

GMAW manual weld speeds vary according to the weld size and location, but they are generally around 30″ per minute. Throughput can be increased by using robotic welding. GMAW welding yields the best results on materials like the following:

  • Stainless Steel: For stainless steel sheet metal, Pulse MIG welding reduces spatter. The electrode does not come into contact with the pool during Pulse MIG welding. An electrode adds molten metal to the pool with each pulse of the current, which alternates between a high and low level.
  • Carbon Steel: For carbon steel, MIG welding is preferred over TIG welding due to its speed. It can also be used to join parts that do not fit closely together. Typical weld examples include outside corners that require dressing.
  • Aluminum Sheet Metal: To achieve a TIG-like weld appearance with aluminum, a pulse MIG machine is used with a special assist gas. The surface scale on aluminum must usually be removed before welding to avoid dust and splash marks.

Shielded Metal Arc Welding

Also known as stick welding, shielded metal arc welding (SMAW) uses a consumable electrode with a metal rod at its core. The arc formed between the electrode and the base metal produces the heat required. Disintegrating flux coatings release vapors that act as shielding gases and provide a protective layer of slag. Both prevent atmospheric contamination of the weld area. During the welding process, the metal rod inside the electrode melts, forming a molten pool that creates the weld.

You can control several variables that affect the width and height of the weld bead, the amount of spatter, and the penetration of the weld, making SMAW welding results easier to control. Stick welding is also more cost-effective than other methods, such as TIG. With its portability and versatility, it can be used in any position and with any thickness of sheet metal. 

There are some downsides to SMAW welding, such as slag created during the welding process and slower speeds (3” to 6” per minute), but as your proficiency develops these issues are easier to control.

  • Stainless Steel:  Stick welding stainless is easy in flat and horizontal positions, but uphill, it can be challenging. Metal drops seem to fall off faster when the rod gets hot, the arc force seems to drop, and the bead crowns. To avoid these problems, set the amperage at the lower range of the required heat level so that the rod doesn’t get too hot and deposit metal at a more rapid rate.
  • Carbon Steel: Stick welding is compatible with all grades of carbon steel, from 0.30 to 0.90%. Depending on the grade, it may need preheating and post-welding heat treatment to prevent cracking.
  • Aluminum: Aluminum is more complicated to stick weld than steel, and the results may not be as aesthetic as you’d like, but it can still be done. Aluminum’s high thermal conductivity and low melting point pose many welding challenges, so you need to apply more heat to the weld pool although the melting point is lower. Getting the right heat requires varying the amperage output on your stick welder, and you’ll need to keep a shorter arc. Be sure to use moisture-sensitive electrodes designed for working with aluminum.

Is It Better to TIG or MIG Weld Sheet Metal?

Sheet metal comes in different varieties, some of which are more suited to one welding method than another. If you’re working with stainless steel, TIG welding will yield the clean visual results you’re looking for. You won’t want to use it on carbon steel, though, because it’s a comparatively slower process.

MIG welding, on the other hand, doesn’t yield attractive results on stainless steel. If you’re working with aluminum, you’ll want to use a MIG machine with a special assist gas. With carbon steel, however, MIG is the recommended approach due to its higher speed.

VeriForm Inc.: Your Sheet Metal Welding Experts

For every project, VeriForm Inc. employs only CWB-certified CSA W47.1 and W59 welders, along with a certified welding engineer. Our on-staff CWB-certified welding supervisors will also supervise your work to ensure the best results for your project. Let us use our experience and in-house efficiencies to prepare and ship your welded sheet metal products, so you have them when you need them. To learn more, please visit our website, call 519-653-6000 or contact us online. 

Can You Weld Carbon Steel?

November 17, 2022

Carbon steel is an iron-carbon alloy with up to 2.1 wt.% carbon. Although carbon steels do not require minimum content of other alloying elements, manganese is often present. The copper, silicon, and manganese content should not surpass 0.6 wt.%, 0.6 wt.%, and 1.65 wt.% respectively. There are three types of carbon steel based on carbon content: low, medium, and high.

At VeriForm, Inc., we are often asked whether carbon steel can be welded. The answer is yes, but depending on the type, you may have to take certain approaches and precautions during the welding process. High carbon steel in particular is crack-sensitive and is prone to significant changes in its mechanical and physical properties after welding, so it is typically considered difficult to weld. However, even high-carbon steels can be welded without problems if you understand the characteristics that make different welding procedures necessary. 

Considerations When Welding

Carbon steel is primarily composed of iron, but there are several other elements that can be added (carbon, for instance) that alter its weldability. When welding a project, it is crucial to understand what type of carbon steel is being used. Weld failure can result from ignorance of important variables, such as the added elements or carbon content range in each grade. 

Welding carbon steel requires the following knowledge:

  • Carbon Content: This content ranges from almost 0% by weight to around 2.1%, depending on whether it’s low, medium, or high carbon steel. Low-carbon steel like C1008 is typically the easiest steel to weld at room temperature. Preheating and post-heating are usually required for medium carbon steels such as C1045 while high carbon steel will most likely require more thorough preheating and post-heating processes to avoid cracking. A special welding filler metal may also be required.
  • Carbon Equivalency: A carbon equivalency formula takes into account other elements in the steel that can affect weldability. The higher the carbon equivalent, the less weldable the carbon steel is. Carbon equivalencies are generally more of a concern with alloy steels.
  • Cooling Rate:  Choosing the right carbon steel to weld also depends on its weld cooling rate. Weld cracking can be exacerbated by high cooling rates. With carbon steels with higher carbon contents and other elements in the carbon equivalency formula, cooling rates should be slowed to prevent weld cracking. Weld cooling rates can be affected by the thickness of the steel as well as ambient temperature.

It is important to note that there are some elements in carbon steel that are not conducive to welding, no matter how much preheat or filler metal is used: 

  • The presence of lead may contribute to solidification cracking, so welding should not be performed on leaded steels.
  • Sulphur and phosphorus can also cause weld cracking. Carbon steel with a small amount of sulphur or phosphorus can be readily welded; however, steel with more than 0.05% of either could develop solidification cracks. A high level of sulphur and phosphorus makes free machining steels like C1141 unsuitable for welding.

Can You Weld Carbon Steel to Steel?

For many applications, stainless steel is an excellent choice. However, it can be expensive when you want to fabricate large workpieces. A lower-cost carbon steel can therefore be used for non-essential parts and frameworks in larger fabrication projects to help reduce costs.

A strong bond between carbon steel and stainless steel requires special attention to details like heat, filler material, and joint design. Joint preparation, root openings, and preheating are crucial, as are maximum interpass temperatures. In addition:

  • Stainless steel requires close monitoring of heat input. It is necessary to control the heat and limit the time in the sensitization temperature range. In areas affected by too much heat, corrosion resistance will be reduced. 
  • Different filler metals are required when welding dissimilar metals. In order to prevent an unsatisfactory alloy from forming, stainless electrodes with higher alloy content are used. 

For these types of projects, you want to ensure that you work with a skilled and reputable Ontario steel manufacturer.

Which Welding Method is Best for Carbon Steel?

Low and medium-carbon steel is typically the easiest metal to weld. There are different techniques you can choose from.

Arc Welding

One of the most common welding methods for low-carbon steels is an arc or stick welding. During arc welding, a high current passes through a pair of cables attached to the machine’s live and earth terminals. A flux-covered electrode is clamped into a spring-loaded clamp on the live cable. Another clamp secures the earth cable to metal workpieces. Intense heat is produced when the electrode is brought close to the metal. The heat melts metal at the weld point, and the resulting melted flux pool prevents contamination of the weld through oxidation.

Gas Metal Arc Welding

Gas metal arc welding, or MIG, is another common carbon steel welding method. This process works similarly to arc welding, except that the electrode is a continuous wire strand that is fed into the welding point by the welding machine. Weld pools are shielded from contamination by a constant stream of argon gas or argon/helium mixture. 

Gas Tungsten Arc Welding

Gas tungsten arc welding, or TIG, is less commonly used, but still a highly effective means of welding carbon steel. Because of its versatility, argon has become the most popular gas used for TIG welding carbon steel and non-alloy steel. It is easy to initiate the welding arc, making it ideal for all types of arc initiation systems.

VeriForm Inc.: Experienced Carbon Steel Fabricators

The versatility of carbon steel makes it suitable for a wide range of applications. VeriForm Inc. provides quality carbon steel parts on time using state-of-the-art equipment and decades of industry experience. Over the years, we have acquired a reputation for product excellence and short lead times.

Our team can assist you throughout the entire process, from the initial design phase to the fabrication of your custom carbon steel part to shipping your finished product, ready for installation. To learn more, please visit our website, call 519-653-6000 or contact us online. 

What Kind of Sheet Metal is Used in HVAC Duct Fabrication?

November 3, 2022

Veriform blog image what sheet metal for HVAC Ductwork. Rolled HVAC duct sheet metal.Ductwork fabrication is the process of fabricating customized parts for a building’s HVAC system. Due to their individual designs, homes and commercial buildings all have their own unique heating, cooling, and ventilation needs, which are accommodated by ductwork made from certain types of specialty metal. This blog examines how these ducts are made, what kind of sheet metal is used, and how VeriForm Inc. can produce the results you need.

How are Sheet Metal Ducts Made?

Duct fabrication sheet metal can be fabricated into a variety of shapes, including but not limited to: 

  • Straight oval pipes
  • Straight round pipes
  • X, Y and Z connector pieces
  • 90-degree elbows
  • Half sheet rectangular pipes

Fabrication of sheet metal ductwork involves cutting and forming. With cutting, shears and high-definition plasma equipment are used, while in forming, brakes and presses apply force to shape the material. With this equipment, precise cuts and bends can be created to create specific shapes and position ductwork around obstacles.

One of the most common solutions is rectangular metal ducts, which are formed by combining two bent pieces of sheeting. First, the flat pieces of metal need to be cut to the desired size using a plasma cutter or cutting machine. The sharp edges are then folded inward by another machine. The sheet is then shaped into an L or tube. Rectangular ducting is usually made to standard sizes, but custom sizes can also be created.

Another common option, round metal ductwork, is made using a different process. To begin the process, sheet metal is placed into a coiling machine. To make the pipe airtight, the machine fuses the edges together. Next, the pipe is cut to the desired length.

What Sheet Metals are Used for Ductwork?

Aluminum and galvanized mild steel are the two most common types of HVAC sheet metal.

Galvanized Mild Steel

Galvanized mild steel is highly pliable and can be formed into nearly any shape. This makes it an especially useful HVAC sheet metal for systems with unusual designs or installation requirements. A zinc coating protects the material from deterioration due to corrosion and rust. This ensures the longest possible lifespan in a ductwork system.

Suitable for industrial, commercial, and residential applications, galvanized mild steel can be easily cut, formed, and fabricated. Once fabrication is complete, the ductwork is wrapped in an insulating material to enhance performance and provide sufficient protection against air loss, thereby reducing energy costs. In addition to creating better airflow, galvanized steel sheet metal duct fabrication prevents mold and fungus growth.

Aluminum

The versatility of aluminum makes an ideal duct fabrication sheet metal, since it can be formed into sheets easily. Compared to traditional steel, aluminum is lightweight, making installation much easier, and extremely corrosion-resistant, which is why it is often used in outdoor applications. A typical aluminum sheet comes with pre-insulated panels, and sections are attached at the seams using aluminum tape and glue.

VeriForm Inc.: Sheet Metal Fabricators for HVAC Systems

At VeriForm Inc., we have a full-range metal fabrication service that can customize your sheet metal ductwork to fit your unique application. Our expertise in shaping, rolling, and cutting duct fabrication sheet metal allows us to deliver high-quality products with short lead times. 

In addition to these capabilities and custom ductwork fabrication, VeriForm Inc. also offers bulk duct fabrication, which allows us to supply large quantities of sheet metal ductwork right when you need it and at highly competitive prices. To learn more, please visit our website, call 519-653-6000 or contact us online. 

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