Consider new technologies
The construction industry outlook remains strong in many sectors, but a continued shortage of skilled labor is a key challenge on many jobsites — one that may prevent contractors and structural steel erectors from completing projects on time or even competing for some projects.
There are two ways to address the lack of skilled welders: Recruit and train more welders into the trade or be more efficient with the workforce already on the jobsite.
A conversion to wire welding processes is one lever contractors can pull to improve productivity and efficiency. More companies are transitioning from stick welding to wire welding on construction jobsites, due in part to the significantly higher deposition rates and travel speeds wire processes can deliver. These gains can be realized while still meeting high weld quality requirements and improving jobsite safety.
Following some key best practices for wire welding in the field and utilizing the right technologies can help optimize efficiency and reduce weld defects — so projects can be completed faster.
Tip No. 1: Make adjustments remotely
On structural jobsites, welders may need to make frequent adjustments to welding parameters to get the best results. When the welder must leave the weld joint and walk to the power source to make changes — perhaps up or down ladders or several flights of scaffolding in the process — these trips can add up to several hours wasted every day while also increasing the risk of injury.
Welding technology on the market lets welders make parameter adjustments right at the weld joint with a wire feeder or stick/TIG remote, resulting in more arc-on time, higher quality welds and a safer jobsite.
Utilizing this technology also reduces the need to continually move racks of welding power sources on the jobsite, a time-consuming and expensive task that typically requires an electrician and crane time.
Tip No. 2: Eliminate cable length voltage drops
One common issue on the jobsite is addressing the voltage drop that can occur in weld cables. Voltage drops happen due to resistance in the weld circuit, which is caused by distance, number of connections and connections that are corroded or dirty.
Typically, the longer the leads and the more connection points, the more resistance in the weld cable. The resulting voltage drop can lead to arc performance issues unless operators compensate for the drop, and this can lead to potential weld quality issues.
In conventional equipment, operators must manually adjust for this by setting the voltage higher than necessary at the power source to ensure they get the voltage they want at the feeder. This is often a guessing game, requiring welders to set a certain voltage, weld for a bit, then either radio another worker or return to the power source to adjust voltage again before walking back to weld more. This may happen several times before the right level is dialed in.
This wastes time and can lead to questions from the quality control inspector as to why the voltage at the power source is set higher than the weld procedure allows.
This time and hassle can be eliminated. Cable Length Compensation (CLC™) technology, available on XMT® 350 FieldPro™ welding systems from Miller, ensures that the voltage welding operators set is the voltage they get — even hundreds of feet from the power source. The power source measures the resistance in the weld circuit, calculates the voltage drop in the weld leads and makes the necessary adjustments. This process happens automatically once the operator sets the voltage and before the initial arc strike.
To help optimize arc performance and quality on the jobsite, it’s also important to use the proper size cables, make sure all connections are tight and free of corrosion, and keep weld cables straight and uncoiled during welding.
Tip No. 3: Troubleshoot wire feeding issues
Wire feeding issues can stem from numerous factors. Knowing the reason will help determine the best course of action to fix the problem.
- Choose the right drive roll: When selecting the drive roll size and type, consider the size and type of wire. Tubular wire is softer and requires a knurled drive roll, which has teeth to grab the wire and help push it through. However, knurled drive rolls shouldn’t be used with solid wire because the teeth will cause shavings to break off, which can clog the liner. Use a smooth, V-groove drive roll with solid wire. Taking the time to swap out the drive roll to match the wire helps promote consistent wire feeding and reduces maintenance on the MIG gun.
- Set proper drive roll tension: Setting the tension too tight can deform the wire. Too little tension can cause wire slippage. To set proper tension, release the tension on the drive rolls, then increase tension while feeding the wire into a block of wood. Continue increasing tension one half-turn past wire slippage. It’s essential to properly set the tension each time the drive roll is changed.
- Trim the liners: Arc instability, birdnesting and burnback can result from liners that are kinked, worn, the wrong size or partially plugged. Blow compressed air through the liners to remove dirt and debris and to improve feeding performance. Promptly replace the liner if a blockage is found, and always trim the liner per the manufacturer’s recommendation.
- Redesigned inlet guide: Feeder technology has improved over the years, resulting in smoother and more consistent wire feeding. Miller wire feeders use an inlet guide designed to reduce wire drag coming off the spool for more consistent wire feeding into the drive rolls — for improved wire feeder performance.
Tip No. 4: Deal with dirty power
What’s referred to as “dirty power” can happen when inconsistent primary power is fed to a welding machine. Portable generators can be a source of dirty power on the jobsite since they may not provide a smooth electrical wave.
Generator technology has improved over the years, making dirty power a less common problem. Since many jobsites still use older, legacy generators, it’s important to look for welding solutions designed to protect against dirty power.
One example is Miller® Auto-Line™ power management technology, which allows the machine to automatically adjust for inconsistencies in the primary power being applied to the machine without impacting the output. Even if incoming voltage varies widely, the circuit ensures a steady welding or cutting arc.
Also, be aware that transformer-based equipment often requires greater power consumption on a jobsite. Newer welding power source technologies can provide much greater power efficiency and save in operational costs. It’s possible with some larger engine-driven welder/generators to power up to six smaller welders at once.
Tip No. 5: Keep a focus on safety
Several of these welding technologies, including the capability for complete control of parameters at the weld joint, help improve jobsite safety.
Out of 4,693 worker fatalities in private industry in 2016, 991 or 21.1 percent were in construction, according to the Occupational Safety and Health Administration. Falls were the leading cause of deaths in construction in 2016, at 39 percent of fatalities.
First and foremost, preventing jobsite accidents impacts employee safety and well-being. Improving safety can also have a financial impact by reducing the cost of worker downtime, insurance or workers’ compensation payments. Jobsite safety records may also be reported in some contract bidding, which means contractors with poor records can have a harder time winning bids.
Improving jobsite productivity
On construction jobsites, it’s all about staying ahead of schedule and delivering quality projects within budget, while keeping employee safety a priority.
As a skilled labor shortage impacts the industry and competition for contracts intensifies, contractors can use some best practices — along with more productive welding processes and new technologies — to help improve productivity, safety and quality.