Underwater welding has many applications and it is a very dangerous job that requires numerous skills. In this article we’re looking at the skills, as well as the different types of welding used underwater. It also briefly describes some of the welding supplies used in underwater welding. Continue reading to learn more about underwater welding and the profession as a whole.
How Does Underwater Welding Work?
There are two types of underwater welding, dry welding and wet welding. Dry welding features a sealed hyperbaric chamber around a structure that needs to be welded. The chamber is filled with gas so it can expel the water and create a dry atmosphere to perform the weld. The chamber needs to be pressurized to the correct level to prevent decompression sickness in the welders.
There are instances when welder-divers don’t have access to hyperbaric chambers or when urgency requires an immediate repair. In these instances, wet welding might be used instead. Wet welding relies on the release of gaseous bubbles around an electric art to shield it and prevent any electricity from conducting through the water.
The insulating layer of bubbles protects the diver and the welding area, which requires the diver to have a distinct set of skills to perform the weld to its full potential. Bubbles can also disturb the welding pool and the welded joint can cool too quickly due to the heat dissipating throughout the surrounding water. This increases the risks of defects, such as cracking. Underwater welding uses direct current rather than alternating current and it is safer for underwater welders welders.
Underwater Welder Training
It is difficult to ignore the risks of underwater welding, but these risks mean that underwater welders are some of the best-paid professionals, regardless of profession. Many underwater welders become professional welders before learning commercial diving.
However, once they realize the pay increase, they are quickly attracted to the career. Before enrolling in becoming an underwater diver, you should learn both the welding and diving aspects of the job. After you are comfortable with these skills, you can seek further training from an accredited institution. Training can take years to complete and underwater diving is a highly specialized profession that requires a ton of effort.
Types of Underwater Welding
A variety of welding processes can be used with both wet and dry underwater welding.
Shielded Metal Arc Welding
Shielded metal arc welding is also known as stick welding and it is often used in underwater welding. It is highly versatile and features cost-effective properties. In it, welders create an electric arc between the electrode and the structure that needs welding. Then it melts and deposits material into the joint. The electrodes and the base material must be clean to perform the weld correctly and the diver should inspect the area for obstructions or other safety hazards before performing the task.
Flux Cored Arc Welding
This type of welding uses a filler material tube with a flux at its core. The electrode wire automatically feeds through the welding gun and allows for an accurate and controlled weld. This method is used for materials including cast iron and metal alloys, such as nickel alloy.
Friction welding uses heat and friction to fuse materials and divers can perform this type of welding underwater.
Dry Underwater Welding
This type of welding method depends on the size of the hyperbaric chamber used.
Habitat welding uses a small chamber and hot work represents one of its most common uses. Gasses get pumped through the chamber continuously to maintain a breathable atmosphere and it keeps the pressure slightly higher than the pressure outside the chamber. This pressure difference prevents dangerous gasses and combustible hydrocarbons and the transportation of toxic fumes and larger habitats can accommodate two to three divers at a time.
Pressure welding applies explosive force or friction to cause the weld. It is a solid-state welding process that includes diffusion welding, explosion welding, gas welding, resistance welding, ultrasonic welding, and friction welding.
Dry Spot Welding
Dry spot welding includes chambers placed throughout the weld area that create a dry atmosphere and the electrode is placed in the chamber to create the weld.
Dry Chamber Welding
Dry chamber welding is similar to habitat welding and it uses a hyperbaric chamber to create a dry atmosphere for the weld. However, in these instances the chamber is smaller than in habitat welding and only accommodates the upper body of the welder. Dry welders employ the shielded metal arc and flux cored arc welding similar to wet welding.
Dry Welders Also use:
Gas tungsten arc welding:
Gas tungsten welding is also referred to as TIG welding and it uses non-consumable tungsten electrodes to create an electric arc and a different wire for the filler material. This technique creates high-quality, durable welds but it requires many skills.
Gas metal arc welding:
Metal arc welding is also known as MIG welding and it uses a welding gun to automatically feed the filler wire while pumping a shielding gas to protect the weld area.
Underwater welding is often used for offshore and marine applications. Much of this work gets carried out in shallow waters or by moving structures to dry areas first. Welding structures at further depths can save the cost of removing structures from the water and dry docking costs. Underwater welding not only creates these cost advantages. It can be used for emergency repairs.
When used to weld fully or partially submerged marine structures, underwater welding can be used for ships, dams, oil rigs, pipelines, bridges, and other applications. Underwater welding techniques are also used in applications related to nuclear power stations, rivers, canals, and other structures.
How Much Do Underwater Welders Make?
Because of the dangers associated with the job, underwater welders can make high salaries. Actual wages are determined by experience, certifications, location, and depth of work. All things considered, the wage for underwater welding can range from $25,000-$230,000 per year.