July/August 2003
Torchcutting may seem like a no-brainer processing activity, but there’s much more to it than just lighting up. Here, experts offer some hot tips for safe, productive torching.
By Robert L. Reid
Hand-held cutting torches have long been one of the most familiar processing tools in scrap metal operations. “Even today,” notes the Handbook of Recycling Techniques, “no scrap yard is without cutting torches.”
But this very familiarity can lead to problems, especially when processors overlook the level of skill and amount of precautions needed to effectively and safely torchcut scrap metal, industry observers note.
Too many scrap processors seem to feel that “if you can light a torch, you know how to run it,” says J. Jones, training specialist for Victor Equipment Co. (Denton, Texas), a leading supplier of torches to the scrap industry. But Jones believes that many scrap operators don’t light their torches correctly, and they fail to recognize that the education and skill of the torchcutter is the most important factor in good torching. Conversely, poor skills or training can make “the guy holding the torch the most dangerous factor,” he states.
Various engineers and service providers at another torch equipment manufacturer report essentially the same thing—that “there’s a general misunderstanding among users in scrap yards” about critical safety and performance issues with torches.
And ask Mike Mattia, ISRI’s director of risk management, about torchcutting safety and he can more easily list examples of scrap yards that need a good torching program rather than those that already have one.
So, what are the elements of safe and successful torching? Here’s a quick guide compiled from various industry observers and users.
Proper Positions and Precautions
The first step in good torching should probably be a step back—to take a look at the material you’re cutting and the people who’ll be doing the cutting.
What you cut is important because different materials can require different levels of skill and varying safety precautions. Just torching some I-beams or flat pieces of steel? Even a novice burner can probably handle that, users report. But if you’re trying to cut up old pieces of equipment, farm vehicles, or other oddly shaped or angled material, then you need a more experienced torchcutter, explains Larry Davis, secretary/treasurer at Gaby Iron & Metal Co. (Chicago Heights, Ill.). Likewise, D.H. Griffin Wrecking Co. Inc. (Greensboro, N.C.), which operates both scrap and demolition operations, always lets torchcutters learn their craft on material in the scrap yard—where a mistake usually just involves extra work—and saves the more experienced cutters for things like building demolitions where the wrong cut could be dangerous, says David Griffin Jr., vice president.
The type of material also helps determine your safety requirements. If you’re cutting up old radiators, for instance, do it outside, advises ISRI’s Mattia. Radiators are mostly cut up for nonferrous metal such as aluminum or copper, which is often processed indoors, but torching radiators can also pose an enormous risk for lead exposure. So, as Mattia sees it, “You’ll never make enough money torchcutting that radiator indoors to purchase all of the air-handling systems that OSHA will require to exhaust those lead fumes.”
Indeed, Mattia argues that all torchcutting should be done outdoors, even torching as routine as working on a truck bumper in the scrap yard’s maintenance shop.
At D.H. Griffin, the potential for lead exposure from old steel covered with lead paint or lead-based coatings means that all torchcutters must wear some kind of respirator. The policy used to cover only metal that might actually cause lead exposure, notes David Griffin Jr. That proved difficult to control, however, because a torchcutter could move back and forth between beams that had lead paint on them and other beams that did not. So the new rule became: “Any burning—no matter what—you wear a respirator,” Griffin says.
Most torching jobs require only a half-mask respirator with HEPA filter cartridges, notes Evelyn Walker, D.H. Griffin’s safety coordinator. Certain materials, though, have such elevated levels of lead—the paint on old bridges, for instance, can be 60-percent lead by weight—that the firm’s burners need to wear a full-face respirator on those projects, Walker says.
The larger respirators offer an added benefit in the way of greater comfort for the user. Mike Mattia knows of at least one scrap processor whose torchcutters prefer a full-face respirator with supplied air even when a half-mask provides sufficient protection. The supplied air keeps them cooler, he says, noting that “it’s like having a fan on either side of the face.”
Other safety gear for torchcutters includes all-cotton or fire-retardant uniforms—never polyester or polyester blends because those will literally melt to the user’s skin if struck by a flying ember, Mattia warns. He even recommends returning any uniforms from your supplier that don’t arrive with a legible label so you can identify the garments’ material.
“If you can’t read it, reject it,” he states.
Flaps to cover pockets, leather gloves and arm protection, as well as “spats” or “chaps” to protect boot laces from sparks and embers are also recommended by various users.
Torching experts also advise taking a good look at the scrap you’re about to cut, at how it’s positioned on the ground or how well it’s supported once you start cutting. R.J. Torching Inc. (Clarkston, Mich.), which provides torching services to scrap operations such as Omni-Source Corp., likes to have the metal laid out so the torchcutters can easily work around large pieces of metal, without having to climb over anything to get to the spot they want to burn, says Jason Roughton, vice president and head of operations. He also suggests maintaining a clear area around a piece that could fall over so the cutter has room to get out of the way.
“Once you cut it loose,” Roughton warns, “it’s up to gravity then.”
Likewise, torching veterans warn against cutting anything that’s hanging directly over your head since such items have no place to fall but on top of you. Other hazardous scenarios include cutting a tightly coiled spring, burning off the end of an unsupported piece of steel so that it drops on your foot, or cutting the supports holding up a wall or other structure so that it topples over on you or another employee, Mattia notes.
Also watch out for potential problems when material ends up in an unexpected position. Mattia recalls one incident in which an old underground storage tank with an unobstructed opening in its side was accidentally rolled over so that the opening was pressed against the ground. The tank sat that way for several months, until a torchcutter tried to cut it apart and instead blew it apart by igniting the residual fumes trapped inside.
It Doesn’t Start With the Spark
Now that you’ve looked everything over, it’s time to light the torch. Keep in mind, though, that lighting a cutting torch properly involves more than just opening the gas valves and igniting the tip with a spark from a striker. For one thing, each manufacturer has its own way of defining “proper” lighting, which depends on the type of gases used and the type of torch as well environmental factors such as whether the torch is being lit indoors or outside in a breeze.
In general, though, there are some basic steps to follow:
First, check the equipment to be sure the hoses for the oxygen and the fuel gas as well as devices such as regulators are properly connected and not leaking—and make sure you use a regulator. Some users try to get by without a regulator in the mistaken belief that the extra pressure will improve performance. All it really does is increase the danger. The flipside of that are the scrap yards that Victor Equipment’s Jones has seen in which users add numerous Y-connections to run more and more torches off the same regulator, which ends up restricting the flow of gas too much.
After checking the equipment, the next step is to purge the hose lines “by opening the valves for a few seconds to allow gas to flow completely through and ensure there’s no mixed gas in the respective hoses or segments of the torch,” another manufacturer says.
Purging the lines is especially critical because normal atmospheric air contains 21 percent oxygen, notes Jones. So if you try to light the fuel gas with atmospheric air still in the line—even if you haven’t opened up the oxygen valve yet—you could still get a backfire that burns up back in the torch, he says.
Jones recommends opening the fuel valve just a little—about one-eighth of a turn—then lighting the tip with the striker. Continue by opening up the oxygen valve a small amount, followed by a little more fuel, then a little more oxygen, then fuel—going back and forth between the gases until the operator gets the flame adjusted the way he likes it, Jones says. When using acetylene as the fuel gas, however, adjust the flame until black soot stops coming out the end of the flame, he adds.
At that point, the acetylene flame is correctly adjusted and the oxygen can be mixed in.
While the initial purging of lines is an important safety concern, the ultimate balance of oxygen and fuel gas is also critical for the torch’s performance. The oxygen itself is what actually cuts the metal, Jones says, while the fuel gas mainly helps create a preheat flame to bring the base metal to its kindling temperature. Once the base metal reaches a kindling temperature of 1,500 to 1,600 degrees F at the surface of the metal, a stream of pure oxygen does most of the work. “It’s an exothermic process,” Jones explains, “in which heat generated from the burning steel is transferred to the steel itself, so the oxygen can continue to burn the steel.”
Moreover, the volume of oxygen—more so even than the pressure—“is the key factor in the amount of material you can burn as well as how fast you can burn that material,” Jones says. Noting that it takes 4.65 cubic feet of oxygen to burn one pound of steel, he adds that too much oxygen in the preheat flame will produce an oxidized flame that burns hotter. Though some scrap operations seem to think hotter is always better, in fact it simply wastes oxygen.
Burning Issues
Operator training is a critical issue for the actual cutting, with most scrap operators relying on hands-on practice with a torch under the supervision of more experienced burners. At Gaby Iron & Metal, for instance, new burners need to learn how to work at a consistent, steady pace, says Larry Davis. Don’t try to cut too fast, he advises, or you’ll get ahead of the hottest part of the metal and not actually burn anything.
It takes about six months for a new operator at R.J. Torching to gain the skills needed to move up from torching simple pieces to more complicated jobs, such as cutting up industrial machinery, notes Jason Roughton.
Likewise, D.H. Griffin finds it can take anywhere from several months to even years before a burner is able to tackle the most difficult scrap—though once they gain that experience, the best burners can be as much as 50-percent better than an average torchcutter, says David Griffin Jr.
While hands-on training is important, Victor’s Jones recommends adding a classroom approach as well. This could cover equally essential topics such as how gases work and the proper selection of tips, torches, and regulators for different applications. Moreover, an expert burner will learn to “listen” to his torch and “translate what it’s telling you,” Jones says.
Suppose, for instance, that the torch pops and goes out, then starts whistling? This can mean that the torch is actually still burning—the flame is just back up inside the torch. “If the operator isn’t aware of this and he shuts down the torch with the fuel gas first, he continues to feed the fire with the pure oxygen,” Jones cautions.
Likewise, many scrap burners seem to think that a torch isn’t burning well if it’s not “screaming.” That screaming sound, however, actually means there’s too much pressure at the torch tip, which can create turbulence that reduces the effectiveness of the cutting stream.
There also seems to be a “a general misconception that the bigger the tip, the faster you can cut,” notes an engineer with another manufacturer. As a result, many scrap torchcutters put oversized tips on their tools, which wastes both fuel gas and oxygen.
Other concerns during burning operations include the need for good communication between the torchcutters and someone operating a grapple or magnet to move large or heavy pieces of scrap, says R.J. Torching’s Roughton. The crane operator and torcher are often “working within 10 feet of each other, so they’ve got to know where each other is and how to communicate what they want done,” he notes. For instance, the crane operator needs to understand the torchcutter’s hand signals for flipping over a big piece of scrap—something that R.J. Torching handles by usually bringing its own cranes to a work site.
In addition to wearing personal protection equipment such as respirators, torchcutters need to watch out for unsafe practices such as wrapping the hose around their arm or leg for better leverage or straddling the hose. Each can lead to a serious accident if a fire backs up into the lines.
Also, don’t let the torchcutter work too closely to the fumes generated by burning metal. Lead particles don’t travel far, notes ISRI’s Mike Mattia, so even using a longer torch can help protect a worker from possible lead exposure. Some firms even use wind socks to determine which way the breeze is blowing, then position their torchcutters so the fumes blow away from them, Mattia adds.
At the End of the Day
When it’s time to shut down the torch, users need to gradually turn down both the fuel gas and oxygen valves until there’s just a small flame, says J. Jones. Then they must remember to completely turn off the oxygen first—otherwise they risk feeding an internal fire. This shutdown procedure also gives the operator a quick check of the torch valves for leaks.
Safety remains a concern even after the torch is extinguished, though. That’s because of torching’s potential for lead exposure—in this case, from ingestion rather than inhalation. So workers need to keep all food, drinks, and cigarettes out of the work area while torching is in progress. Then, make sure the burners have access to hand-washing stations and vacuums with HEPA filters to clean off their uniforms before leaving the designated torching zone and, say, entering the lunchroom.
Normal soap and water isn’t enough to clean off lead particles, says Mike Mattia, so workers should use a phosphate-based cleaner such as dish detergent. All lead-exposed clothing should also be left behind at work for laundering to prevent exposing people beyond the workplace.
To monitor lead exposure, OSHA requires periodic air sampling and blood-level tests for torchcutters. It’s also a good idea to monitor for cadmium, says Mattia, since cadmium particles are often generated along with the lead particulates—something a particularly sharp OSHA inspector will know and test for during an inspection.
Fortunately, a good torching safety program can keep your company in compliance. At D.H. Griffin, the company’s strict safety enforcement has produced a noticeable decline in blood lead levels over the years, says safety coordinator Evelyn Walker.
For another scrap firm, making smart decisions about torching also benefited the bottom line. R.J. Torching handles about 98 percent of the burning at OmniSource’s Fort Wayne, Ind., scrap facility, notes Mike Richmond, plant manager. The relationship between the two companies is good enough to let R.J. sort Fort Wayne’s cut scrap by size and commodity, he notes, adding that OmniSource does a final quality check before shipping the material to customers. This novel torching relationship enables the facility to “know what the numbers are going to be per ton,” which makes it easier to plan and purchase raw material, Richmond says. •
Robert L. Reid is managing editor of Scrap.
Torchcutting may seem like a no-brainer processing activity, but there’s much more to it than just lighting up. Here, experts offer some hot tips for safe, productive torching.