Vertaslag History

 

When the Arcmatic Welding Systems noticed that no welding equipment manufacturers were taking advantage of this newly developed NGI-ESW welding process, they decided to take on the task of developing the type of equipment that would be necessary to make the process successful.

To understand the reason why NGI-ESW was such a good starting place for Arcmatic, one must understand a little bit about the history of Electroslag welding, and the problems encountered by what is now referred to as the “Standard Electroslag Welding” (ESW) process; understanding this history will accent why the NGI-ESW welding process is so important to the welding industry.

The management personnel of Arcmatic Welding Systems have been involved in Structural Steel Welding, and have gained a combined experience of over 75 years in production welding.  Some have been involved in the Electroslag welding process since the late 1960s.  They had first hand knowledge of why the process failed to become widely used in this country.  They also knew that:

If a system could be developed to quickly train unskilled operators

If the mechanical equipment could be setup quickly and easily

If the operator could simply pre-program all of the welding variables

If a system program could control all of these variables during welding operation

If the system could produce consistent quality from weld to weld

If all of the applicable welding codes could be passed easily

The process had the potential for great success in the welding industry.  The only problem remaining for Arcmatic would be to design the system.  With these things in Mind, Arcmatic set about developing their version of an Electroslag welding system, using the NGI-ESW process.  Arcmatic called the combination of the equipment and the process, VERTASLAG welding.

In their quest to use the new NGI-ESW process, Arcmatic realized that the equipment used in a laboratory environment to develop the process might be perfectly suited for research, but not necessarily best suited for a production.  To test the reality of this idea, Arcmatic started out using equipment, similar to that used by Oregon Graduate Institute to develop the NGI-ESW process.  Initial production welds were made in a local structural steel fabrication plant, using standard equipment, universally available in the welding industry.

These initial production applications, employing the NGI-ESW process (using off-the-shelf equipment), pointed the way for the need to develop welding systems that were easier to operate, faster to setup, and capable of producing repeatable quality, from weld to weld.  It also demonstrated that Arcmatic’s modular mechanical and electrical components could be used to produce these systems. 

The idea to design a line of modular components seemed simple at first.  However designing, debugging, and field-testing a full line of the mechanical and electrical components turned into an expensive and time-consuming project.  The equipment not only had to be designed, and tested, but also accepted by academic, governmental, and trade agencies.  These agencies were needed to sanction the equipment and process so the equipment could be used to fabricate projects, such as high-rise building components, bridge components, Heavy Equipment components, and more.

Arcmatic had one major advantage in developing this new line of VertaSlag welding equipment.  One of the developers also the owned a small fabricating plant, Cofab Steel, located in Vallejo, California.  The close relationship between Cofab and Arcmatic gave Arcmatic a sympathetic partner to develop, debug, and test each new product in a shop environment on actual production applications.  Cofab could bid jobs that could challenge the newly created designs

In production welding, all process variables must be defined and controlled.  If this is not done, the variables, which are left uncontrolled, will eventually cause weld defects.  The repair of these defects may become so expensive, the process would become unviable.  To maintain control over all welding variables encountered with VertaSlag welding, Arcmatic has: researched and defined these variables, developed solutions for their control, and incorporated these solutions into a modular, programmable, computer controlled electronic control system. This control system allows a computer to activate the correct control variable at the proper time in the weld sequence – eliminating the need for the operator to rely on his memory for every weld.

After Arcmatic’s electrical and mechanical modular components were developed, Arcmatic set about the task of incorporate these modules into the VertaSlag control system that employs the NGI-ESW welding process.   Time has confirmed that this approach was the perfect place for Arcmatic to start.  Arcmatic then about the task of designing and developing special clamping fixtures, to hold their standardized modules to be used to perform the NGI-ESW welds.

The first VertaSlag welding system was a clamping fixture for Fabricators to weld moment plates (stiffeners) into high-rise building columns.  This fixture allowed the welding operator to place the fixture over the weld, by turning a handle, to automatically clamp the water-cooled copper shoes onto either side of the weld joint - simultaneously aligning the consumable guide tube in the center of the weld cavity.  This fast setup allowed one welder to make as many as 16-stiffener welds in one eight-hour shift.  Prior to the VertaSlag Stiffener Welding System, existing methods allowed an operator to make only 2-to-3 stiffeners per eight-hour shift (depending on the thickness of the stiffener). 

After developing the VertaSlag Stiffener welding system, it became apparent that moving the fixture from weld-to-weld and dragging the heavy cable behind, could quickly exhaust the welding operator.  Arcmatic then designed and developed an Articulated Boom and Boom Lift that could carry the weight of the fixture and cables, to make it easier to move the equipment from one stiffener to the next.  In addition to the Articulated Boom, Arcmatic designed the Portable VertaSlag Welding System with an angularly adjustable boom height.  This unit was designed to give portability to the Stiffener Fixture assembly, but required the end user to worry about cable and hose transportation around the shop.

The Northridge earthquake occurred in January 17, 1994 in the Los Angeles basin – one year after Arcmatic started in business.   A large number of weld failures were detected that required extensive repair.  These repairs turned out to be extremely costly – reportable over a billion dollars - almost all of them welded with gasless flux cored wire FCAW-S.  Even though zero defects were discovered in any of the million or more continuity plates made on high-rise buildings in the LA basin, much greater restraints were put on the ESW process.  Almost all the cracks were in welds made with the FCAW-S welding process, yet very little restraint has been put on the use of that process in welding continuity plates.  After Northridge, structural engineers became far more demanding with the ESW welding process.  With the ESW welding process establishing such a successful record in two earthquakes (Northridge and Loma Prieta) the restraint put on the process by NEMA 350, NEMA-353, and OSHPD is very puzzling to this very day.  These extremely expensive seismic tests were developed to test any welding procedures planned for welds on building in seismic area.  To date, Arcmatic VertaSlag welding process has been able to pass all the qualifications tests for the AWS D1.8 Seismic Code that was issued as a result of NEMA 350 and 353.  Even the high impact requirements which required 20-ft. lbs. @ -20-deg F were passes with ease.  After Northridge, Arcmatic has made 100s of thousands of stiffener welds on high-rise buildings, but for some reason, there are still some agencies that question the most successful, trouble-free welding process that has ever been use in the United States.

After the VertaSlag Stiffener Welding System had been perfected, Arcmatic began development of the Bridge Builder (otherwise referred to as our VertaSlag “Butt-Tee Fixture”) designed to perform heavy plate “Butt Welds” and “Tee Welds” with the VertaSlag welding process.  The Bridge Builder can be mounted on the end of the Articulated Boom for easy handling.  It can also be mounted on the Portable VertaSlag Welding System.  The Bridge Builder was designed primarily to weld Bridge flanges.  A special Water-cooled copper shoe holding bracket is placed over the bridge flange to hold the water-cooled copper shoes in position on either side of the weld and to provide a mounting surface for the Butt-Tee Fixture”.

A welding operator, using the Bridge Builder to weld flanges together can weld between 8 and 12 flange weld per 8-hour shift.  Using the conventional method, which is usually a portable submerged arc squirt welder, an operator can usually weld one or two flange welds per 8-hour shift.  Bridge flanges 6-to-8-ft high can be first welded vertically-up, at a weld speed - Vertical Rate of Rise (VRR), of 1-1/2-to-2-IPM, and then stripped to individual flange widths.

The name, VertaSlag is not just the brand name for Arcmatic products.  In all instances, the name refers to the combination the system and the process.  In this instance, it is the mechanical and electrical control over the NGI-ESW process.  Arcmatic has entered the structural steel and bridge fabrication markets with compete packaged welding systems called, VertaSlag welding.  A customer can purchase individual modules to build their own welding system, or purchase a complete turnkey package from Arcmatic.  In addition to the modular components and turnkey packages, Arcmatic offers a full line of welding consumable products that meet all of the requirements for NGI-ESW welding and Submerged Arc (SAW) Welding.  The company has over 15 patent-pending claims for its modular components controls and welding fixtures to build automated welding systems.  Not just for VertaSlag, but for all wire feed welding processes.  The VertaSlag welding system feeds from one to four wires at a time; allowing plate thicknesses from ½-inch thick to 12-inch thick (and thicker) to be welded in one single pass.  VertaSlag can produce finished weldments between 4 and 10 times faster than conventional flux-cored wire and submerged arc welding.