Renting welders

Ready to do a variety of jobs – from steel fabrication work to pipe welding to carbon arc rehab work – rented welders address your need for additional units.

While stick electrode units comprise an estimated 75 to 80 percent of rented construction welders, many welding equipment manufacturers see a trend toward wire-feed welders. “Some building codes, especially in California, even spec wire-feed welding,” says John Luck, product manager, Miller Electric.

“Almost anything that can be stick welded can be wire welded,” says Matt Fleming, rental sales manager, Lincoln Electric. “Contractors would do well to look at wire welding because it’s much more productive than stick welding. Wire processes can produce significantly higher production rates and you don’t have the starts and stops you do with stick welding.”
Wire-feed units do have their drawbacks, however. They require additional setup time, higher initial equipment cost, regular consumable maintenance (such as tips and liners) and the welding crew member usually has to stay close to the wire feeder.

Most welding units rented by contractors fall into the 160-to-500-amp range. “We see rental companies buying the heavier-duty welders,” Luck says, “since they give them so much more capability than smaller units.”

You’ll usually find a rented welder in the three-to-five-year age range. Before you rent, make sure the welder looks like it’s been taken care of and runs well. “Five years is a good age for a rented welder as long as it’s been well maintained,” says Mike DeBrino, manager, WDB Rental/Volvo Rents, Hamilton, Ohio. “My welders now are all less than 15 months old.
“Most of our welder rentals are by the month. We just have an eight-month construction period, and customers have multiple jobs they use them for so they tend to keep them out.”

Source of power
Welders are also classified by power source: electric and propane – which can be used indoors – and gas and diesel for outside work. (See chart on page 54.)
When renting, though, keep in mind there’s no performance difference between electric or engine-powered units, says Doug Miller, Multiquip’s welder product manager.

Gas welders are usually smaller and thus more portable, adds Miller. “For example,” he says, “our GAW-135H welder can be mounted to service trucks or on high-reach baskets and is great for a wide variety of utility welding applications.”

“Most of my renters ask for a certain power type – diesel, gas or propane – rather than a brand,” DeBrino says. And his customers lean toward large diesel welders, especially if they’re working outside because they need the power, the cycle times and the constant voltage of a diesel welder. “Once they get used to a welder they like,” he says, “they usually don’t want to change.”

“Diesel welders are usually bigger and have more power,” says Mike Glaude, Rental Service Corporation. “They offer good fuel consumption, and diesel as a fuel is readily available on a jobsite.”

What to keep in mind
While most contractors who rent welders know exactly what they want when they pick up the phone, there are some general points to consider.

Know exactly what size of welder you’ll need. “Sometimes contractors overspec their welders, renting a 400-amp unit when all they need is 250 amps,” says Jeff Moureau, rental operations, Miller Electric. “This costs them money since 400-amp welders are naturally more expensive to rent.”

Many rental centers carry a variety of safety items for welders.

On the other hand, your job might include carbon arc gouging, usually used to repair defective welds or for joint preparation. In this instance, you would need a higher amperage welder.

Figure out if you want to run any tools or other units off the welder. If you also plan to use the welder as a generator, tell your rental company. Not all machines can run every tool. While some engine drives can provide a variety of auxiliary power options, others have limited output or only DC capabilities. Pumps especially will require a lot of power and can’t be run off every welder.

Be aware of any potential savings. “An engine-drive unit with at least 8,000 watts lets you run a plasma cutter off its auxiliary power, and an engine drive with at least 12,000 watts lets you power another electric welding machine,” Moureau says. “This is an economical way of putting two arcs on a single site or creating a welding/cutting fabrication shop in the field.”

Look at economic alternatives to multiple arc welding. Multi-arc welders reduce jobsite clutter, Moureau says, along with costs for transportation and fuel. And the cost of renting multi-arc welders (which come in two-, four-, six- or eight-arc versions) is usually well under renting a number of single-arc welders to accomplish the same task.

Consult your welding crew. Brand preferences can run strong among people who weld and they may feel more comfortable using a certain model. “We know some customers will only accept certain brands,” says Cotton Guerrant, La Porte, Texas, branch manager for United Rentals. Still keep in mind, however, there may be advances in welding technology your welding crew doesn’t know about.

Check out what’s new. Renting a new welder offers a good chance to check out technology and determine if it will give you any productivity gains. Glaude cites JLG’s Sky Welder, for instance. “It’s a lot safer because you don’t have the lead and ground cables scattered around the jobsite since they’re contained in the boom,” he says. “It’s also cheaper because you’re renting two machines – an aerial lift and a welder – but only paying one rental. And there are productivity gains – you don’t have to go down to the ground to move the welder. You have everything right there.”

And older rental machines may not have the latest technology, Fleming adds. As an example, he mentions Lincoln Electric’s Chopper technology, which electronically approaches a pure DC output for the smoother arc preferred for such operations as pipe welding. “Pulse welding has also been refined in the past 10 years,” he says. “Inverter-type electric welders are more reliable, have a higher output than in the past and are much more portable than transformer-type electric welders.” A 350-amp, transformer-type electric machine, for example, will weigh about 400 pounds. The same amperage machine in an inverter version will weigh just 95 pounds.

Know your field conditions. If you’re welding out in the open, make sure your rented welder is shielded from blowing dust. If wire welding, consider the use of “suitcase” wire feeders that encase the device and keep out contaminants. In addition, consider renting a welder with remote controls if site conditions require welding up in the air or inside a tank.

Be aware of safety. Welders generate electricity, so the safety considerations are many. Those welding must wear insulated gloves, face shields and body protection and stand on an insulating material. “We sell these products at our rental stores, which makes it convenient for our customers to operate safely,” says Keith Dressendorfer, Gulf region district manager for United Rentals.

Inspect cords and cables to make sure they stay in excellent condition during your rental. “They shouldn’t have any burrs or cuts on them,” says Guerrant. If a cable’s in poor condition, and has bare spots, it can result in minor burns or other injuries.
Make sure your rented welder has a ground fault circuit interrupter, Luck says. “An OSHA inspector can shut a job down if you don’t,” he adds.

Match the length of your ground and lead to your welder’s amperage. Keep the welder cables as short as possible, close together and down low, such as on the floor. If the cable is too small, it will heat up and create power flow resistance.

Typically renters ask for 150 feet of lead cable and 50 feet of ground cable, Dressendorfer says. “You always want to work as close to the machine as you can,” Guerrant adds. “The amount of lead and ground cable you use will depend on the size of machine you rent.” There are other variables, including the gauge of the metal being welded and the age of the cable.

“You can run a lot more cable with a 500-amp unit, where the 250- to 300-amp units are limited to 300 feet,” Glaude says. Also note the lead and ground are rented separately from the welder.