Numerous factors – from supply chain issues that affect project timelines to a skilled labor shortage – have many construction contractors looking for more efficient ways of doing business.
While the welding operation is typically a smaller part of many construction projects, productivity gains can be found there. Using more efficient welding processes and technologies can help contractors complete jobs faster, compete for more bids and save time and money.
One change that contractors can make to improve efficiency is converting from stick welding to wire welding processes on the construction jobsite. Wire processes offer significantly higher deposition rates and travel speeds compared to stick welding, and these gains can be made while still meeting high weld quality requirements.
In making the move to wire welding, consider these tips to ensure you’re using the right technologies and best practices to help optimize efficiency and maintain high weld quality.
Tip 1: Take advantage of remote technology
Construction and structural jobsites are often sprawling, crowded places. When operators leave the weld joint and walk to the power source to adjust parameters, the hours of wasted time add up. Frequent trips can also increase the risk of injuries from slips, trips and falls, especially when welders must go up and down ladders or levels of scaffolding. On some jobsites, the trip back to the power source could be 200 ft. to 300 ft. or more across a busy work area.
Look for welding technology that allows welders to make parameter adjustments right at the weld joint using a wire feeder or stick/TIG remote. This increases arc-on time, helps improve weld quality and results in a safer jobsite. With ArcReach technology, operators can make adjustments at the weld joint with their wire feeder or remotely without the need for a control cord, simplifying cable management and reducing maintenance costs on the jobsite.
In addition, when operators can easily make parameter changes where they’re working, there is less chance they will make do with less-than-optimal settings, which helps them produce high-quality welds.
Apex Steel, a structural steel contractor based in Kirkland, Wash., uses wire welding processes. Adoption of ArcReach technology on many Apex jobsites helped the company improve productivity and safety while also maintaining consistent weld quality. Poor weld quality on structural jobsites can result in project delays, added labor time for weld rework and replacement, and lost time to relocate parts or equipment back to the weld or repair area for that rework.
The company, which must meet stringent American Welding Society (AWS) D1.8 structural welding code for seismic regions on many of its building projects, saw significant time savings with the remote welding technology. Each welder saved up to two hours per day by not walking back to the power source to make adjustments. Multiplied by even 10 welders on a jobsite, that’s 10 to 20 hours saved per day, resulting in greater arc-on time and productivity.
Tip 2: Understand the sources of wire feeding issues
Wire feeding problems occur for a variety of reasons. Understanding the system and common causes of wire feeding issues helps reduce troubleshooting time and determine the best solution to the problem. Take these steps to optimize wire feeder performance:
- Choose the right drive roll: Consider the size and type of welding wire when selecting the drive roll size and type. Tubular wire (like flux-cored wire) is softer and requires less drive roll pressure. A knurled drive roll has teeth to grab the wire. This is recommended to help push the wire through the gun liner. It is important to note that knurled drive rolls shouldn’t be used with solid wire because the teeth cause shavings to break off and possibly clog the liner. Use smooth, V-groove drive rolls with solid wire. Swapping 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: Too much tension can deform the wire, while 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 to just past the point where wire slippage stops. Be sure to inspect the tension each time the drive roll is changed.
- Trim and clean the liners: Liners that are kinked, worn, the wrong size or partially plugged can result in arc instability, birdnesting and burnback. Blow compressed air through liners to remove dirt and debris and to improve feeding performance. Also be sure to replace the liner if a blockage is found, and always trim the liner per the manufacturer’s recommendation.
- Use a good inlet guide: Wire feeder technology has improved over the years. Today’s feeders offer smoother and more consistent wire feeding, even on the jobsite. Wire feeders from Miller use an inlet guide designed to reduce wire drag coming off the spool for more consistent wire alignment into the drive rolls – improving wire feeder performance.
Tip 3: Eliminate cable length voltage drops
Another common issue with wire welding on the jobsite is the voltage drop that can happen in weld cables. Voltage drops occur due to resistance in the weld circuit, which is usually caused by distance, the number of connections or connections that are corroded or dirty.
The longer the weld leads and the more connection points in the weld leads, the more resistance that occurs in the weld cable. That means an operator sets a certain voltage at the power source but does not get that voltage at the weld joint. This voltage drop can result in arc performance issues or potential weld quality issues unless operators compensate for the drop.
In conventional welding equipment, operators must manually adjust for voltage drop by estimating the amount of expected drop and then setting the voltage higher than necessary at the power source to ensure they get the voltage they want at the feeder. This can be a guessing game, requiring welders to set a 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 found.
Eliminate that time and hassle with the right equipment. Cable length compensation (CLC) technology, available on select Miller power sources, ensures that the voltage 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 automatically.
In addition to taking advantage of technology, it’s important to set yourself up for success by using the proper size and length of cables, make sure all connections are tight and free of corrosion, and keep weld cables straight and uncoiled during welding. All of these steps help optimize arc performance and quality.
Tip 4: Deal with dirty power
A source of headaches on the jobsite is “dirty power,” which can happen when inconsistent primary power is fed to a welding machine. Portable generators are a common cause of dirty power since they may not provide a smooth electrical wave.
Generator technology has improved over the years, making dirty power less common. But if the jobsite still uses older, legacy generators, you may want to consider newer solutions designed to protect against dirty power. Some welder/generators include power management technology that 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. The technologies in newer welding power sources can provide much greater power efficiency and save operational costs. It’s possible with some larger engine-driven welder/generators to power up to six smaller welders at once.
Now more than ever, staying ahead of schedule and completing quality projects on budget is critical for construction contractors. Following some best practices and taking advantage of more efficient welding technologies can help improve productivity, safety and results.