by Nestor Gula
Increasing weld production in small and medium sized firms
Small to medium sized welding shops must always push for maximum productivity from their workforce and their machines. It is the only way to stay competitive. When encountering problems, or seeking to enhance productivity, a big mistake made by many is to throw money at problems in the hope that this will make everything OK.
While some solutions do require a cash infusion, it is the way the money is applied that makes the difference. Buying the most expensive welding power source might solve your welding productivity issues, but buying the right welding power source will most definitely solve these issues.
There are quite a few ways that new welding technology can help small to medium sized fabricators improve productivity. “Many small to medium sized fabricators generally don’t have the manpower to have resources dedicated to optimizing production, and smaller shops may also face a shortage of skilled welding operators,” says John Leisner, segment manager at Miller Electric Mfg. Co. “To help address these challenges, newer welding technologies and processes can offer more consistent penetration to the component, less spatter generation, which reduces the time and money spent on cleanup, less heat generated by the process, which results in less distortion of the part for better fit-up, and simpler user interfaces that are easier to set and use, which provides advantages for shops that have less experienced welders.”
A welding shop can optimize production by bringing in new welding power sources with advanced pulse waveforms or data monitoring functions. “Advanced pulse waveforms can offer many benefits, including lower spatter and heat input,” says Scott Stanley, national marketing manager at Lincoln Electric Co. of Canada. “And of course, data monitoring can provide crucial information for production planning and bidding on jobs. Both technologies are available to every manufacturer, not just the big guys.”
Welding technology has evolved to enhance productivity by simplifying and optimizing process setup, “eliminating the time previously taken to adjust and fine tune the welding arc,” adds Ian McLaren, global product manager robotics automation at ESAB. New functions, like ESAB’s smart MIG (sMIG) enable “operators to begin welding with a well-tuned arc after setting wire diameter and plate thickness. It also adapts to the welder’s technique taking into account gun angle and stick out to provide a smooth repeatable weld each time. Such a function enables beginner or less skilled operators to focus on welding and not waste time with adjustments. It also instills confidence that the operator has the correct settings to ensure proper penetration.”
Bringing in new technologies to the shop can bring great advantages even without a change in the welding processes. “Short-circuit MIG welding is the most commonly used process in fabrication. There are newer technologies available that not only make short-circuit MIG easier to run and more forgiving to less experienced operators, but also provide less spatter and more consistent heat and penetration into the part,” explains Leisner. “So, even though the process hasn’t changed, the technology used for the process makes it more productive and efficient.”
Companies with older power sources can still see some benefit from these systems. “A 20-year-old power source, probably a transformer based monster if it’s that old, can offer some interesting opportunities,” says Stanley. “If gas or self-shielded flux cored wire is being used, a switch could be made to a metal cored wire, or an S-6 hard wire with a higher Argon gas blend, as just one example. Under the right circumstances, submerged arc could even be a possibility. One of my favourite cost reductions was a customer running an automatic flange welder with a gas shielded flux cored product. We were able to switch to running submerged arc on the same automatic flange welder using a high torque feeder, a submerged arc welding gun, and a small flux recovery system. In addition to increasing deposition rates, we also lowered fume generation by switching from the gas shielded flux cored product to submerged arc. It was a win-win.”
The welding machines themselves are not upgradable, but will benefit by using newly developed wire or gases. “There’s not much that can be done with the equipment itself, but in many applications, there are newer wires or different gas blends that can help improve productivity or reduce spatter, ultimately resulting in less operator time spent on non-value-added activities,” says Leisner. “For example, there are newer metal-cored and flux-cored wires designed to significantly improve deposition rates or to run smoother and produce less spatter, even when using the same welding equipment. Keep in mind that new welding equipment offers much greater power efficiency compared to 20-year-old machines, which can result in significant annual energy savings per machine.”
If a new machine is not in the cards for your shop, new wires can bring productivity gains from older machines. “Using a premium filler metal can improve many aspects of production efficiency,” advises McLaren. “For example, premium aluminum and solid wires feed more smoothly and consistently so operators can weld longer and worry less about wire shavings that clog gun liners, lead to erratic feeding and increase the number of burnbacks. Premium gas-shielded tubular wires can improve travel speeds, increase deposition rates, reduce spatter, enhance operator appeal and improve weld quality.”
To find the right filler wire for a specific application, work with a filler metal expert.
Correcting mistakes and rework is one of the costliest functions that any business must perform. In welding, this is no different. “The farther along in the production process that a defect or missed weld goes, the more expensive it gets to bring it back and repair it,” says Leisner. “Defects can be more common when using newer materials that are thinner, and therefore more sensitive to heat, which can easily lead to distortion or bad parts fit-up if the wrong process or parameters are used.”
Newer machines with greater flexibility in settings can help avoid these problems. “It’s important to control the amount of heat that goes into every part, and this is made significantly easier by using new welding equipment and technologies that offer an easier-to-use welding arc and an intuitive user interface for adjusting parameters,” says Leisner. “Heat input is critical, especially with the new higher strength materials that are thinner. Paying attention to heat and using proper settings and technique can significantly reduce welding defects.”
A question to consider: if one is upgrading the power source should the shop go full forward and consider automation?
“A small or medium sized shop should evaluate automation regularly from time to time,” suggests Stanley “With offline programming software, a robotic system is becoming an option for smaller shops with lower production runs, because they are much easier to program, and easier to change from welding part A to part B.”
Automation might seem like a good idea, but be cautious, advises Leisner. “Shops should consider automation on every project, with the key word here being ‘consider.’ Not every project will be worthy of automation, but it’s important to consider it. There is a real and growing pressure on all manufacturers to become more competitive in a market where there are fewer and fewer qualified welders. In addition, smaller companies may face additional pressures, such as rising health insurance, safety and benefits costs, and the need to maintain consistent, high quality welding.”
New advances in software and programming make automation look tempting to small and medium sized shops. “Using what is called “self-learning robotic technology,” unique parts that took 25 or more hours to fabricate now take 45 minutes,” says McLaren. “Good candidates for self-learning robotic applications include those that have a notion of family in their components. Structural steel I-beams provide a prime example. A typical beam will have a W section (main beam), a start plate and an end plate, a few stiffeners and some connector plates. With just a few common parts, their dimensions can be adjusted to build an infinite number of I-beams that satisfy any need.”
If purchasing a custom welding cell or an off the shelf solution is not in the budget, there are smaller steps a shop can take to increase productivity.
“Short of a robot, a great option for customers is some form of welding positioner. Larger parts can be mounted in a two or three axis welding positioner,” says Stanley. “Instead of using (and waiting for) a crane to become available, the welder can easily manipulate the part into the optimal position for welding, which can also increase deposition rates. This is particularly useful for industries like heavy fabrication. The efficiency improvements are always shocking, and it’s a much easier jump than a full robotic system.”
Purchasing new equipment might seem like a great solution, but providing training to the workforce might pay off exponentially.
“In most shops, the majority of time isn’t spent actually welding, but rather it’s in the preparation for welding and the post-weld cleanup,” says Leisner. “When welding operators are trained effectively in proper technique and setup, the post-weld process becomes significantly shorter, and therefore less time and money is spent on it. Knowing how to set the machine is critical to this. While large manufacturers generally have weld procedures, many small to mid-sized shops do not. Without weld procedures, welding operators may not know the best spot to set the machine, and improper settings can lead to inefficiency and more time spent on non-value-added activities such as grinding and post-weld cleaning.” SMT