I’m willing to bet that, if you aren’t part of the welding profession, the idea of doing so underwater might get you to gasp in shock and disbelief. Sure, you may not know a thing about welding, but you know water and electricity just don’t mix! How on Earth is it possible for you to weld underwater? What is hyperbaric welding, and how can it possibly be safe?
Hyperbaric welding is the process of welding underwater in a hyperbaric chamber, which helps spare you the nasty “shock” that would come from mixing water and electricity otherwise. It is a hugely important skill because there are plenty of settings that require hyperbaric welding, such as dams, oil rigs, ships, and even some nuclear power stations.
Wherever there’s a structure that requires metal fabrication for something beneath the water, underwater or hyperbaric welders can meet the challenge.
Here, you can find an article from our website about 7 steps for avoiding electric shock when welding underwater.
Underwater Welding 101
As a practice, hyperbaric welding is actually older than you might imagine. It was first pioneered way back in 1932 by the Russian metallurgist Konstantin Khrenov. It works in a similar fashion to conventional, above ground welding insofar as it also involves melting different joints and metal parts together via an arc.
The big difference is, of course, that you are doing so underwater, despite the fact that our intuition would seem to tell us that mixing electricity and water is a very bad idea.
Before you continue reading, here is an article we wrote about the different types of underwater Welding.
Underwater welders are trained in special techniques for controlling the electrical flow of their tools in such a way as to mitigate that risk. As expanded upon below, they do this via dry and wet welding techniques.
These require special training to learn. However, the actual welding process itself is similar in many respects to conventional welding.
As such, if you’re already a welder or commercial diver, you’ll have a leg up in training, and be able to focus more on the half of the skill set that you still need to obtain.
In addition to welding skills, hyperbaric welders need to be able to move with ease underwater, which means taking and passing commercial diving lessons. It usually takes between 2.5 to 6 years to become a certified underwater welder.
During your training, you’ll learn not only commercial diving techniques and how to use them in the context of hyperbaric welding, but complementary skills such as cutting, rigging, fitting, and underwater photography.
The Risks and the Rewards
There is no denying that underwater welding can be a dangerous business. Any time electricity and deep sea diving and pressures are involved, so too is a great deal of risk present.
The slightest slip up could lead to anything from a botched job to electrocution to the bends or other diving-related issues.
That said, the rewards for a successful career as an underwater welder are potentially immense. Divers can often make between $25K and $80K, though six figure salaries for experienced hyperbaric welders is not uncommon.
Moreover, you have the satisfaction of knowing that you’re engaged in work that is constructive, rarified, and a distinct challenge that not everyone can do.
Hyperbaric welding can feel like a blend of engineering excitement, Indiana Jones, and Twenty Thousand Leagues Under the Sea all welded together in a unique aquatic career.
If you already possess a diving or welding skillset or are looking for a fresh challenge with a flush pay scheme for experienced personnel, the potential rewards of underwater welding well exceed the risks.
Dry Versus Wet Welding
The two main types of underwater welding are dry and wet welding.
The first of these demonstrates a misnomer and misconception about underwater welding, which is that it is all done underwater. On the contrary, while much of the work is indeed done while a welder is underwater, since it makes use of many conventional welding techniques as well, it can also be performed in dry conditions.
Dry welding involves making use of a hyperbaric chamber, wherein much of the welding takes place. This is also why hyperbaric welding is another variant of underwater welding.
This enables the welder to work within a dry atmosphere while still beneath the water that contains a mixture of different gases that would not be possible otherwise. This allows the welder to weld in a controlled, reliable setting.
That said, hyperbaric chambers can be expensive, which is why wet welding can be a solid cost-effective alternative. Practitioners make use of a shielded electrical arc that utilizes an attached power supply.
Due to the risks and difficulties it poses, wet welding is less preferred than hyperbaric welding. For one thing, wet welding can lead to quality issues, with the welded joints cooling too quickly as a result of the water causing the heat to dissipate rapidly.
This can lead to the welded metal cracking or the joints becoming defective. For that reason, it is of the utmost importance to make sure that the rate at which the metal cools when welding is watched carefully and highly controlled.
It is practically impossible to achieve the level of care needed for this when welding in the open water.
Within that main division of wet versus dry underwater welding, there are several different types of techniques. Just as there is a different task for every job, so too are there different ways to get the job done when faced with a task that requires underwater welding.
Three of the most common hyperbaric welding techniques include:
- Shielded Metal Arc Welding: This is easily the most common type of underwater welding, being used more than 90% of the time, especially when wet welding is involved. It is also known as stick welding, because it involves using cylindrical nodes to create an electrical arc. It can be used for aluminum, stainless steel, and a whole host of other metals, making it one of the most versatile underwater welding techniques.
- Flux-Cored Arc Welding: This technique uses a spool that provides a constant feed, giving welders some vital filler metal, including cast-iron and nickel alloys.
- Friction Welding: This uses – you guessed it – friction to generate the heat necessary for successful hyperbaric welding. It is used for various thermoplastics and metals.
A blend of diving skill and engineering ingenuity, hyperbaric welding brings the magic of metalworking under the sea.