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Efficient extraction

Fume extraction guns offer features that can improve flexibility and results for the MIG welding process

by Andy Monk, product manager for new products, Bernard

 

 

 

 

Limiting exposure to welding fumes is an increasingly important issue for many welding operations as it provides a cleaner, more comfortable work environment and helps companies stay compliant with industry regulations.

 

With the aim of protecting employees against potential health hazards in the workplace, OSHA and other safety regulatory bodies set the allowable exposure limits for weld fumes and other particulates, including hexavalent chromium.

 

Although some companies may choose a centralized fume extraction system designed to protect the entire shop area, these systems can be a substantial investment and often require installation of new ductwork. In some welding applications, they are not a feasible or efficient fume extraction option.

 

A fume extraction welding gun is a viable alternative in certain applications, such as when the welder is in a tight or confined space or must move often to complete welds on a large part. Welding guns with built-in fume extraction are commonly used in heavy industrial welding, such as truck and trailer, railcar and heavy equipment manufacturing.

 

Fume extraction guns capture the fumes generated by the welding process right at the source, over and around the weld pool. They can be tailored to best meet the needs of a specific application or to welder preferences. Consider these key factors when choosing the right type of gun for the job. Knowing about specific features can help improve gun flexibility and performance in certain applications.

 

A fume extraction gun is a viable alternative for fume control in certain welding applications, such as when the welder is in a tight or confined space or must move often to complete welds on a large part.

 

 

Weight gain

Fume extraction guns are available in a variety of amperages and handle designs. Common amperages range from 300 to 600.

 

Keep in mind that amperage is tied to gun weight. The higher the amperage, the more copper required in the power cable and, therefore, the heavier the gun will be. Along with the added weight, higher amperage guns typically cost more, so it may be a waste of money to buy more gun than necessary for the application. Therefore, the lowest amperage gun possible that still completes the job is recommended.

 

At the other end of the spectrum, buying the lightest fume extraction gun available may not provide the amperage or durability needed for the application. Some lighter and more flexible guns aren’t durable enough for heavy industrial applications. Always consider a gun’s duty cycle rating, and keep in mind that it’s a balancing act between gun weight and durability when choosing a fume extraction gun.

 

Tailoring the fume extraction gun handle and neck to the application and welder preferences can help improve weld pool access and reduce operator fatigue. Most guns are available in curved (shown) and straight handle options.

 

 

Functional features

Various fume extraction guns on the market offer features and capabilities that help optimize fume capture while also providing benefits for operator comfort and ergonomics, gun performance and ease in producing quality welds. When choosing and configuring a fume extraction gun, consider these four options.

 

Adjustable vacuum chamber: The nozzle on the front of most fume extraction guns is covered by a vacuum chamber. The gun can have a fixed chamber or an adjustable vacuum chamber that can be moved to several positions. This provides better joint access and visibility and helps welders dial in vacuum flow to eliminate porosity.

 

Adjustable vacuum chambers can also improve ergonomics as they reduce the need for the welder to position their body in uncomfortable positions to get a better view of the weld pool. Adjustable vacuum chambers that snap into position provide greater durability than friction-fit chambers. These can loosen over time and eventually fall off, requiring replacement of the chamber.

 

Some fume extraction gun manufacturers also offer various vacuum chamber options, such as a short chamber that helps increase visibility and access to the weld pool.

 

Suction control valve: Most fume extraction guns offer a way for welders to control the vacuum suction and optimize gas flow. Look for a gun with a vacuum regulator – often positioned at the front of the handle – that allows welders to balance suction with shielding gas flow to protect against porosity.

 

Flexible, crush- and snag-resistant hose: A vacuum hose designed to be crush- and snag-resistant eliminates the need for a protective hose cover in many applications. This helps reduce overall gun weight and increases flexibility of the hose. However, be aware that some heavy-duty welding applications requiring extremely high heat will always require a leather cover to protect the hose. Note, a gun with a vacuum hose that swivels also improves flexibility, visibility and joint access and helps reduce wrist fatigue.

 

Handle and neck options: Tailoring the gun handle and neck to the application and welder preferences can help improve weld access and reduce operator fatigue. Some brands of guns are available in curved and straight handle options.

 

In higher amperage applications, welders may want to put the gun cable over their shoulder with the gun trigger on the top. Straight handle guns allow for this. When choosing a gun with a straight handle, consider one with a rubber overmold on the handle to help reduce vibration and provide a better grip for ergonomic relief.

 

Some guns also have additional neck options in a variety of bend angles, such as 30, 45 and 60 degrees. This provides even more ability to tailor a gun to specific needs and also improves ergonomics.

 

 

 

Results matter

Some fume extraction guns are designed using a common consumable platform, which means any consumables – nozzles, contact tips and gas diffusers – used on a standard MIG gun or even a robotic MIG gun can also be used on a fume extraction gun.  This offers greater flexibility and helps reduce a company’s consumables inventory. Additionally, it may be important for some companies to choose a fume extraction gun that is compatible with vacuum systems from most major manufacturers.

 

In the right applications, fume extraction guns can help companies maintain compliance with safety regulations and create a cleaner, more comfortable welding environment for employees. When choosing a fume extraction gun, look for features and accessories that provide additional flexibility, time savings and advantages for welder comfort.

 

Bernard