Make it Hot - Dissolving preconceptions about underwater welding


8/4/2019 / USA

A small group of people gathered around the trailer-mounted dive tank. Inside, diver Kirk Hooker of Hooker welding set up a new angle to weld. “Make it hot.” Hooker’s voice came through the speaker slightly distorted, but his team knew what to do. They flipped a lever and replied, “It’s hot.”

Kirk Hooker poses with his demo dive tank
Kirk Hooker with his demo dive tank

The water inside the tank lit with the brilliance of the welding arc. Specks of debris littered the now cloudy water from the hour Hooker had already spent welding inside the tank. While underwater, Hooker is reliant on his team for his air supply, electrical controls, and good communication to ensure he is safe and can do his work. The mobile dive tank he’s using is his patent-pending design. He travels with it to schools, conventions, and other gatherings to demonstrate underwater welding.

Hooker began welding more than twenty years ago. He took his love of the trade underwater five years later after becoming certified with the American Welding Society (AWS.) The idea for teaching and demonstrating underwater welding came to him about four years back when a school asked him to talk to their students about the career. Until then, Hooker Welding did the typical small shop welding for car and equipment enthusiasts and local farms. After that presentation a whole new business model presented itself and he’s been building on that ever since.

With the demonstration over for the day, Hooker gathered his equipment and climbed the ladder out of the tank. The extra hundred pounds of dive gear didn’t seem to faze him in the change from a near-weightless environment to solid ground. Team members were there to help him down the outside of the tank and remove his gear. His two kids and wife watched with the rest of the group, a reminder of the hard work and perseverance that helped make this dream a reality.

Fifteen years as a a commercial diver has given Hooker access to a lot of people in the industry. When he was designing the mobile tank, he reached out to people for advice and specialty items such as the thick aquarium-grade glass that serves as a window to his work. The trailer is outfitted with a communication system and an oxygen delivery system. Commercial divers rarely rely solely on a backpack tank the way a hobby diver does. Part of their gear includes a reserve tank for emergencies such as a severed line. It holds just enough air to get to the surface.

Arc welding underwater mixes electricity and water and is often referred to as one of the most dangerous jobs on earth. What does Hooker think of the dangers? “Sure it can be dangerous, but just like any job with risk, if you know what to do, have the proper tools, and take precautions, it isn’t near as dangerous as people think.”

Some of the most dangerous aspects of the job come from working in man-made structures. I was surprised to hear that they dive inside structures more than in rivers or lakes, and he only works inland, not in the oceans. Inside structures, they have to be especially careful of differential pressure. This happens when bodies of water of different elevations intersect, such as in a dam or other bottleneck. The pressure from the higher elevation compounds, pushing water from one area to the next, often through a small opening. If the diver becomes trapped in this flow, the force of pressure on the body against the opening can cause severe injury or death. 

Many preconceptions about underwater welding are inaccurate but the most common question Hooker gets is, “So what do you weld?” The answer included fixing pipelines as I assumed but they also repair water intakes, chemical treatment lines, and weld steel for concrete forms underwater. Welding is a small part of a commercial divers job, but the welding power supply does more than weld underwater too. It provides the means to cut or “burn” through steel as well.

All of the details built into the trailer and tank allow Hooker to travel wherever necessary. Even his welding power source is a small portable unit that does double duty. Wet welding uses shielded metal arc welding (SMAW) with wax coated electrodes that keep the flux dry until it melts during application. Hooker uses his Fronius TransPocket 180 to weld underwater and to cut through up to six inches of steel or fracture concrete. 

“Burning can be more dangerous than welding. The process uses the arc with pressurized oxygen and a magnesium-cored rod to establish and control the cut. But that oxygen can collect in small pockets that will explode and can blow out a diver’s faceplate.”

Exploding bubbles, differential pressure, what other challenges do welder divers face? Well, the visibility underwater wasn’t just bad for taking pictures. As any welder knows, a solid weld requires keeping a keen eye on the arc and weld puddle. Visibility is the biggest challenge of wet welding. Murky water, lack of light, and floating particulates are just the beginning. The view from inside the helmet is limited, like with a regular welding hood, but welder-divers need to keep track of their environment more than surface welders do. Air bubbles from exhalation and those created by the welding process are constantly obscuring the view. If the diver does get a good position where bubbles aren’t in their face, seeing the weld is still difficult because water is constantly quenching the weld puddle. Keeping a close arc gap is important, and there isn’t a lot of puddles to watch. Maintaining a fluid weld is difficult and creating attractive welds underwater is significantly more challenging than above the surface.

Working underwater is more challenging and everything takes longer. Where a simple T-joint on the surface can take less than a minute, just suiting up in dive gear takes about ten minutes. Based on the dive, an average set of gear weighs a hundred pounds or more. Divers don’t work alone, so in addition to the regular weld and site prep, they have to check their communication system. It takes a team to safely get the diver ready and welding. Even getting to the weld site takes time—whether it’s straight down or several hundred feet into an underwater tunnel. There isn’t such a thing as a “quick weld” when working underwater.

So what about mixing water and electricity? Won’t they get shocked? It’s possible but welder-divers wear gear that helps protect them. Being aware of your surroundings and knowing the location of the welding ground line in relation to the weld site is imperative. “Don’t put your ground behind you. The electrical current will pass right through the water—and you—to complete the circuit.”

Most welders are happy behind a torch, changing parameters and adjusting the arc. A welder-diver has to set all of that up before they suit up. Then they have to rely on their team to adjust parameters on the fly or turn on the electricity—to “make it hot.” Welding anywhere is a solid skill that takes practice, but welding underwater adds levels of difficulty not everyone would be happy. Especially in one of the most alien environments on Earth.

-By Rhonda Zatezalo, freelance writer, Crearies Marketing Design LLC

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