ARNOLD AIR FORCE BASE, Tenn. -- When engineers in the test facilities across Arnold Air Force Base need items fabricated ranging from large platforms to small data-collection devices, they typically turn to the welders at the base Model and Machine Shop to provide the spark needed to get the job done.
Between the boilermakers, pipefitters, ironworkers, sheet metal workers and machinists capable of wielding the torch, around 40 welders call the Model Shop home. This number does not include those in maintenance and operations crews scattered around the base who are also capable of welding as required.
The welders in the Model Shop are spread across different craft sets, but Manufacturing Services Deputy Manager Brad Reid said all support testing and general operations at Arnold.
“The welders support all parts of operations at AEDC,” he said. “Some jobs are building new infrastructure for the facilities, while others are repairing existing infrastructure. Sometimes, it is plant equipment and sometimes it’s temporary systems in support of a particular test. And, sometimes, welding is required to fabricate or modify test articles.”
At its most basic definition, welding is the process of using high heat to fuse metal together. But welders at Arnold perform various types of welding including Tungsten Inert Gas, or TIG, a method of welding in which the arc is maintained by a tungsten electrode and shielded from the access of air by an inert gas. They also conduct metal inert gas welding, or MIG, a method in which the filler metal supplies the electric current to maintain the arc. Like TIG, in MIG welding the arc is shielded from the access of air by an inert gas, usually argon. “Stick welding” is also performed by Arnold welders. This method, more formally known as shielded metal arc welding, manual metal arc welding or flux shielded arc welding, is a manual arc welding process that uses a consumable electrode covered with a flux to lay the weld.
The welders carry out these processes on various types of metals, including aluminum, stainless steel and carbon steel.
Each welder found in the Model Shop is required to pass a welder certification test as a condition of employment.
“They also have to maintain certifications during the duration of their employment,” Reid said. “Certifications are based on the material to be welded and what welding technique will be used, such as MIG, TIG, etcetera. Maintaining the certification consists of performing welding while you are here. A code on the timecard system tracks what and when each employee welds. This data is used to verify that the welder has performed a certain welding process. We call that information the Welder Continuity Report.”
According to Model Shop Pipefitter Mike Riddle, most welders are also required to complete plenty of training before they are allowed to strike out on their own. For Riddle, who has 13 years of experience in pipefitting, this included a yearlong pre-apprenticeship program that he said acts as a “weeding out process” used to determine if a potential welder is mechanically inclined and responsible enough to show up for a job. Afterwards, a would-be welder must complete an apprenticeship that includes five years of classroom instruction and fieldwork during which they will encounter various welding scenarios.
The Model Shop welders support testing at Arnold through the fabrication of piping, meshes and other items used in cells across base. The products needed from the welders depend on the type of test and the facility in which it is conducted. The pipe used for one test may not work for a subsequent test within the same facility, meaning the welders are regularly called upon to make the necessary alterations.
“We’re constantly modifying the test cell for whatever application they’re testing and article they’re testing and whatever the needs are at the moment,” Riddle said.
Riddle said the welders fabricate as much as possible in the Machine Shop based off of the plans provided.
“Even though these test cells have been here for years, they’ll get something in there and they’ll say, ‘We’ve got to have this pipe modified,’” said Mike Lance, Model Shop pipefitter and chief steward for all AEDC pipefitters. “So we’ll fab the pipe up here and then take it over into the cell and install it so that they can do a certain job.”
If needed, the Model Shop welders will go out into the test facilities to make final positional welds and modifications to the product.
“Here in the Model Shop, us pipefitters, we are a dual craft in a way in that we work here in the shop and we do work out in the field,” Riddle said. “A lot of the pipefitters in the actual facilities and the test cells, they specifically work there. We go back and forth. We work here and there.”
Riddle added those from the Model Shop will respond rapidly to the test cells if adjustments are required.
“If the test cells needed something done in a hurry, we would be some of the faster people to get on the site to fix it where they don’t have to send out a request for bids,” he said. “They could call us and we could get up there and have some people on the job site quicker if they don’t have the manpower.”
The Model Shop welders also work to bring older piping installed in base facilities prior to current codes up to modern standards. He said this work may involve repairing welds or replacing welds.
Riddle said the quality of the equipment and welding personnel at Arnold is “second to none.” Because of this, he said efforts are made to keep as much work as possible in-house.
“I think the engineers know what they’re getting when they bring us on board with them – the highest of quality,” he said.
John Adams, an inside machinist in the Model Shop, holds unique responsibilities at Arnold. While pipefitters and other craft skill sets have welding requirements, many machinists do not. Adams is the only true machinist welder at Arnold AFB.
“I’m the only man on base who does what I can do,” he said.
Like other welders at Arnold, Adams works on large structures that may require a crane to move. Unlike anyone else on base, Adams is occasionally called upon to weld pieces that can fit in the palm of the hand. He is responsible for laser welding, a method in which small metal pieces are placed in a machine. From there, Adams looks through a microscope as he fuses together the pieces, which are sometimes less than a centimeter in diameter. These welds are used in the data-collecting rakes and periscopes found in the flame emitted from a tested engine.
“Sometimes we have to weld some very small stuff, some very high-precision stuff,” Adams said. “That’s what I do.”
For Adams, it is this work on minute materials that differentiates his duties at Arnold from those at prior jobs.
“It’s a lot more precision,” he said. “I do a lot smaller work here than I ever have before.”
Along with the MIG, TIG, stick and laser welding, Adams also performs induction and orbital welding at Arnold. He said he enjoys his job due to the variety of his tasks and how they support the mission of Arnold.
“There’s more of a purpose behind what we do here than anywhere I’ve ever worked,” he said.
Reid said the work of the welders is vital to Arnold and base operations could not be carried out without their efforts.
“You can’t maintain and build this place without them,” he said.