Underwater welding is also known as hyperbaric welding usually comes as a surprise to many as the combination of electricity and water is seen as incompatible and hazardous.

However, underwater welding is a lucrative field and one of the most well-paid occupations for commercial divers.

Underwater welding has been around since the 1930s, widely used for maintaining marine infrastructure present underwater. 

Underwater welding can be done in two ways, either directly underwater, or by using a separate dry chamber.

Welding activities generally are quite dangerous, even on dry land. Doing the same activities underwater only increases that danger. That is why to be an underwater welder; a lot of requirements/qualifications are required. 

Inland hyperbaric welders can work on small sea crafts, dams and bridges. On the other hand, offshore welders have to work on ships, oil rigs, pipelines and underwater habitats. They may even have to perform welding work on nuclear power facilities.

 

How to Become an Underwater Welder (Qualifications)

• A career in commercial diving and underwater welding is very rewarding, but truth be told, not everyone can become a commercial diver and underground welder. 
• The industry demands 100% commitment, with long hours of extensive travel, a great attitude and a superior work ethic.  
• It’s important that you are ready both physically and mentally if you want to succeed as an underwater welder 

Aside from being physically and mentally ready, you will also need to have some educational qualifications to practice as a professional commercial diver and underwater welder.

These are the minimum requirements you will need to possess:

• High school diploma or GED
• Ability to swim
• Mechanical aptitude
• Commercial Diving Certification
• AWS Certified Welding Training

Processes Of Underwater Welding

There are two ways underwater welding can be done, It can either be wet or dry. 

Each of these processes is explained below:

 

1. Wet Welding

During wet welding, the diver is expected to do the job directly underwater. meaning no separate chamber is used here.

With wet welding where restriction of movement isn’t restricted (lack of separate chamber), divers can roam around the welding area and work quite easily. However, not all wet welding is advantageous.

 

While wet welding, the diver ensures all welding materials are waterproof and safe to use even when exposed to water. 

One of the most commonly used wet welding techniques is stick welding or shielded metal arc welding.

 

In this technique, an electric arc is used between the electrode that the diver uses to weld metals together, and the metals he wants to weld.

 

ADVANTAGES OF WET WELDING

• It is less expensive.
• No hassle of constructing a chamber for the diver.
• No restriction on movement hence, welders can access the area freely.

 

2. Dry Water Welding

Dry water welding is a common form of underwater welding and is preferred over wet welding. Done in a chamber filled with gases (to dry environment) placed underwater so that the welder stays dry and can work with more precision. 

Cofferdam and Hyperbaric are the two types of dry water welding.

Cofferdam Welding

In this technique, a chamber is fixed and sealed around the welding area. The water is flushed out mainly by using valves.

Hyperbaric Welding

For Hyperbaric welding,  a sealed chamber is placed around the structure that has to be welded,  all the water in the chamber is then replaced with a mixture of gases (usually helium and oxygen)

The pressure is maintained at such a level that the welder or the team of welders do not feel any decompression sickness. Other team members control fans to fill the chamber with clean air.

Employing dry water welding minimizes the risk of welding underwater and gives the welders the option to work with less fear and more precision and accuracy.

But It is usually not always feasible because creating and sealing a chamber as well as replacing the water with gas, are expensive and cannot always be done. In such cases, wet welding is the only option left.

Dry Water Welding Advantages

• Less Risky

 

UNDERWATER WELDING EQUIPMENT

Different welding types require different types of equipment. For underwater welding, the tools and soot have to be versatile and resistant to high impact.

To properly carry out underground welding, a commercial diver requires five major tools;

• Diving helmet
• Diving suit
• Power supply
• Stinger
• Electrodes

Accessories Needed For Underwater Welding 

 

Underwater welders require some necessary attachments and accessories to easily carry out their job. These include;

Diving Knife

A diving knife is an essential tool for many situations, for instance, a diver might need to cut project material, free himself from entanglement, or wedge opens a door. The diving knife does this job.

Umbilical cord

The umbilical cord is where the gas gets pumped to and from the surface to the welder.

Harness

This is important to keep the diver buoyant and in place while doing her or his work.

Compressor and Gas Panel

A qualified team monitors the gauges of gas and ensures that there’s  a steady supply of air that is coming to the underlying diver. Many of them employ low-pressure gas because of low maintenance and an unlimited supply of air.

Bailout Gas

A bailout gas is employed for emergency purposes, this gas is carried by divers as a secondary source of gas supply in case other equipment fails..

Knife Switch

The knife is different from a diving knife. It looks like a simple lever,  It is used while using underwater electric equipment when welding to control the electricity floor from the topside to provide power to your tools. 

Underwater Welding Machine

When it comes to choosing a welding machine, current and amperage need to be put into consideration. 

When carrying out underwater welding, there need to be a constant communication between the diver and a control team Immediately before the diver starts welding, she or he will need to communicate through the radio towards the control team.

This provides a signal to turn underwater welding machines to the right amperage. The required power is dependent on the electrode size. 

 

The Dangers Of Underwater Welding?

Underwater welders have various situations/elements to contend with, elements such as atmospheric gas, gas pressure, specialised diving and welding equipment, electric current supply,  limited space, and so on, expert welder-divers must also be fully prepared to avoid risks and must be ready to handle the dangers associated with underground welding. 

Some dangers of underwater welding include:

• Decompression sickness
• Drowning
• Explosions
• Electric shocks
• Hypothermia

As stated earlier, underwater welding comes with a lot of risks, it is, therefore, necessary to take safety precautions to reduce the risk. 

Some safety precautions that should be taken include: 

• being tethered to the surface, 
• Having another welder-diver to assist the process.
• Be in constant communication with the team throat out the welding process.