Portable Plasma Cutters Help Improve Efficiency for In-the-Field HVAC

Snips will never disappear from the sheet metal worker’s toolbox. They’re small, versatile, simple and easy to carry. However, compared to a plasma cutter, they’re slow and can cause hand fatigue on large projects. In many cases, contractors that require more productive field fabrication tools. The weight and primary power availability have helped limit their use.

Plasma cutters, TIG welders and MIG welders using traditional technology often weigh 80 lbs. or more, occupy several cubic feet of cargo space in a contractor’s truck bed and often require 230V primary power to cut or weld on thick material. If the right type of power outlet is not conveniently located, contractors may need to string hundreds of feet of extension cords and/or weld cables.


Today, mechanical contractors, such as the Hellwig Company, are improving productivity by using inverter-based plasma cutting and welding technology that combines maximum portability and primary power flexibility.

Based in Santa Clara, Calif., the Hellwig Company provides complete mechanical, process piping and plumbing system services to general contractors and businesses. While one division handles process piping, the mechanical contractor division provides a reliable, cost-effective source for sheet metal HVAC ductwork, architectural sheet metal, flashings for ductwork, piping, equipment and water-proofing, as well as metal roofing, louvers and other specialty sheet metal fabrication and installation.

The three latest additions to Hellwig’s tool box are an 18-lb. plasma cutter with a 27-amp output, a 37-lb. TIG/Stick welder with a 200-amp output and a 45-lb. MIG welder with a 180-amp output and an internal shielding gas cylinder. All these products feature inverter technology, which provides three key benefits:

  • Light weight
  • Compact size
  • Ability to automatically connect to 115V or 230V primary power (while 230V outlets can be scarce, 115V power is almost always nearby).

Hellwig learned about these new systems from Javier Campos, administrator of the Santa Clara Sheet Metal Training Center, which trains journeymen for Sheet Metal Workers Union Local 104.

“Portable plasma cutting systems are very useful when putting in an HVAC main trunk and cutting openings to run branches off,” says Campos. “For those jobs where you have a lot of cutting to do after the duct is hung, it saves a lot of time. It’s also useful for punching holes into studs, running conduit and trimming, especially in kitchens where they use a lot of stainless or heavier gauge metal.”

Cutting Speed and Power

To calculate potential time savings compared to snips, power nibblers, saws, cut-off wheels or other mechanical cutting devices, consider the cutting speeds possible with inverter-based plasma cutters in the 27-amp category (the size Hellwig uses).

Plasma cutters provide the benefit of fast cutting speeds on thin sheet metal, yet also have the power for cutting thicker structural components or piercing pipe. Other tools may not offer this combination of speed and cutting power.

The new generation of plasma cutters is about the size of a good lunch pail, according to Tom Born.

Portable MIG Welders

Buck Harris, shop foreman and purchasing agent for Hellwig, agrees. He says that MIG welders “make it much easier for a guy to get up in the tight spots or to get up on a deck instead of loading heavier, bulkier equipment on a scissor lift, which was a pain. I’d say depending on how big of a job you’re on, the time savings could be anywhere from 15 to 25 percent.”

Hellwig was recently called to work on a high school’s stainless steel kitchen countertop and cabinet, which Born needed to cut and lower by two inches. As with most stainless steel products in food applications, codes required TIG welding not for cosmetic reasons, but to leave a smooth radius that can be easily cleaned without providing a foothold for bacteria.

The industry’s most popular conventional TIG/Stick welders with a DC output for welding on ferrous metals weigh more than 300 lbs. They require a fork truck just to lift them onto the truck headed for the job site. Conversely, Hellwig’s new DC TIG/Stick inverter weighs 37 lbs. and can be carried with a shoulder strap.

“Its size, weight and portability make it our choice for TIG and Stick welding in the shop and the field,” says Born. The unit welds at 1-amp for maximum control on sheet metal and thin-wall pipe, yet, “goes up to 200 amps, so you can Stick weld with a full range of 5/32-inch rods if you need to.”

The next time you need to make a clean cut or weld in a remote location, consider using the latest in portable technology. The savings in time and energy will help make these types of jobs more productive for your bottom line.

Article courtesy of Miller Electric Mfg. Co.

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