Power Sources and Self-Shielded Flux-Cored Electrodes
While testing a new welding product for field erection, Helmark Steel Inc. discovered something that would fill a much greater need - a way to add more welding units in its shop without adding another power substation. The problem that this steel fabrication shop, located in Wilmington, Delaware was facing was an increase in work, which meant that fitters needed more welding power sources to accomplish their jobs. For most companies this would just mean purchasing new welding units, but for Helmark Steel, available incoming power could not support more units. Hence, the company was about to make a costly upgrade to the power substation outside its building.
Coincidentally, Helmark was in the process of testing the Multi-Weld™ 350 welding units from The Lincoln Electric Company. These units, marketed for job site and construction work, allow for a number of different welding machines to be run off of one power source. While local distributor Urie & Blanton urged Helmark Steel to try out the units for possible fieldwork, company representatives soon realized that the system could be utilized to fill a unique niche indoors as well. Now both Helmark Steel and its erection sister company, Falcon Steel, are reaping the benefits of improved energy usage as well as the excellent welding performance offered by the Multi-Welds.
"Our main problem was that we were running out of electrical power in the shop and thought our only option was a substation upgrade," noted Bill O'Brien President of Falcon Steel. "We didn't know that technology such as the Multi-Weld existed. Now, we have five or six people welding off of one, 100 amp, 480v outlet as opposed to each welding operator requiring his or her own outlet."
Lee Roth, Quality Control and Safety Director for Helmark and Falcon Steel is equally as pleased with the find. "We are using less power, and, more importantly, no one is waiting to get a machine to do their work. With the Multi-Weld, we can now supply additional machines as required. There is also a savings gained by not moving welding equipment around the shop. The company employs 30 certified welders.
In addition to the purchase of the Multi-Weld units, Helmark Steel has also made a switch in its wire to cut cleaning time by 75 percent per weld. This has made a substantial difference in productivity at the shop and has furthered the company's innovative use of welding products to gain a competitive advantage.
The Construction Business
For more than 30 years, Helmark and Falcon Steels have been in the building construction business. Helmark Steel handles in-shop fabrication of the steel skeleton including beams, columns and braces while Falcon Steel provides on-site erection services. Some of the more-recognizable buildings that the company has completed include the IBM Building in Philadelphia, the Olympic Stadium in Atlanta, and the Federal Office Building in New York City. The projects range from 40 to 60 stories and up to 16,500 tons of steel.
All work performed by Helmark and Falcon is custom. Steel is purchased in 40 or 60-foot lengths from the mill, then fabricated according to specifications by sawing, drilling, burning, bolting and welding into finished assemblies.
Before discovering the Multi-Weld 350 units, Helmark used individual, inverter power supplies for their welding and tacking needs. But now, fitters use the Multi-Weld units with LH 70 electrodes for tack welding various steel members and they also are used for out of position welding when required. Two Lincoln DC-600 power sources are used to supply power to 12 Multi-Weld units.
"What's amazing is the performance remains the same if one, six or eight Multi-Weld units are being used at one time," claimed Roth. "We don't experience any drops in amps or volts. In addition, it is so easy to add new operators, by just plugging into the distribution box. In the past, we would have to hard wire in another power source."
The steel used in the Helmark shop is A36 and A572 grade 50 that ranges from 3/8" to 5" thick. In addition to structural shapes, quite a bit of girder and truss fabrication is also done. While an average girder can run 40 to 60 feet in length, the company has manufactured girders in excess of 100 feet. Trusses average 80 to 120 feet.
By handling all stick welding with the Multi-Weld units, this frees up Lincoln DC-400, 600 and 1,000 power sources, used in combination with LN-9 wire feeders, for all flux-cored finish work. This includes both partial and full penetration fillet welds at high deposition rates. For very large-sized girders, Helmark will occasionally utilize a dual-head gantry and perform submerged arc welding.
With two shifts a day, the Multi-Welds don't get much idle time in the Helmark shop.
Switch to New Wire
Distributor Don Urie at Urie and Blanton was also instrumental in helping Helmark switch to a new wire for its flux-cored welding operations. He encouraged the switch because of the ease of slag removal and the higher deposition rates that could be achieved. After a month of trial, the company converted the shop completely over to NR®-305. By changing from a NR-311 to a 3/32" NR-305, Helmark has reduced clean up time by 75 percent. And, with higher deposition rates, the savings have been even more significant.
"After applying the improved operating factor, actual arc on-time for NR-305 gives us deposition rates of 4.95 pounds per hour versus the 4.2 pounds per hour we were experiencing with the NR-311," stated O'Brien.
The new wire also has superior impact properties and passes the Charpy test for fracture critical work, which means for projects requiring Charpy's, the operators no longer have to change wire. And with the new impact properties, no down time is required for switching between Bridge and Building Fabrication.
For the operators, the wire is smoother running with less spatter. And since it is a flux-cored wire, it requires no shielding gas, which means no changing bottles to hamper production. Also, no bottles mean a safer shop environment. According to Lincoln Electric local representative Bob Sommer, the new wire is saving Helmark $27,000 per year.
The Multi-Weld 350 units are critical in fieldwork because they are lightweight and portable, which means they can easily be moved around the structure. "Our operators can carry the Multi-Welds with one hand. With no ground wiring required, they are very portable and easy to use," commented O' Brien.
In addition, the Multi-Welds allow the parameter controls to be near the operator. "In the field it is a must," stated Roth. "It eliminated the need for someone to holler down to a person on the lower floor to turn the machine up or down. The welder places his machine near the weld joint to eliminate a lot of wasted time."
With one control cable, Multi-Weld units eliminate job site clutter and save money on welding cabling, plus there is less chance that cabling will be accidentally cut.
And, the energy efficiencies realized in the shop have also carried over with the Multi-Weld to the job site. "In incorporating the Multi-Welds, we discovered that we could weld all over the job site off of one power supply," said O'Brien. "This means that we are also saving money on electrical service to the job site which has been a big success." In addition, the operators are not experiencing any drop in power, which tends to happen when all the other trades, start pulling power from the same source.
"In the field, we use Lincoln DC-1000 machines to power up to 10 Multi-Weld units for a combination of stick and flux-core welding," continued O'Brien. "When you look at the DC-1000's amp gauge and it is only putting out 500 amps to power all of these units, by running at half the maximum capacity the life of these machine should be extended considerably. In addition, these machines are very rugged and I know our guys are hard on them."
For job site erection, Falcon Steel ironworkers are using the Multi-Welds and the new NR-305 electrode. Accompanying Lincoln LN-25 wire feeders offer portability when working on these large steel structures. Because of the small, compact size of the Multi-Weld units, they can easily be stored in toolboxes overnight on the job site.
"Once our field welders became acclimated to the Multi-Welds, they were able to make full penetration welds in half the time," stated O'Brien. "Plus, we are achieving excellent quality."
Representatives at Helmark and Falcon can't say enough good things about local distributor Urie and Blanton. "I deal with our distributor almost on a daily basis. We are fortunate to have them, they are a full service dealer, not just salesmen," noted Roth. "Through the years, I have asked them many technical questions and if they did not have the answer, they find it out and get back to me in a timely fashion. On many occasions, they have come into our shop to help our maintenance department or consult on a technical problem we are having. I cannot speak highly enough of them."
Roth also cannot speak highly enough of the Multi-Welds and what the system has done for his shop and field operations. "I would definitely recommend the Multi-Weld to anyone who is having power problems or a company that needs portable, quality welding performance."
Originally written 05/22/01