Underwater welding is a career that has a great deal of promise and a great deal of challenge. It’s not a career for those who are faint of heart. There are many skills that are required of underwater welders. It is essential to have the proper training to make sure that the welder is safe as well as able to do the job properly so that nothing goes wrong later.
There are three kinds of underwater welding. These are wet underwater welding, coffer dam welding, and hyperbaric welding. Each kind is completely unique from the others and has specific processes that have to be followed.Wet underwater welding is done using the manual metal arc welding (MMA) process most commonly. Flux-cored arc welding (FCAW) used to be used in the former Soviet Union. Friction welding has a lot of potential to be used in deep water repair, especially if something needs to be repaired where people can’t go. It mainly is done using robots.
Coffer dam welding consists of a steel structure that is sealed against the side of the structure that is needing to be welded. It is open to the atmosphere and houses the welders in dry air, making it easier to do the welds.
Hyberbaric welding is done by sealing a chamber around the structure to be welded, and then filling it with gas. Helium is commonly used. The gas fills the chamber to a higher pressure than the water around and pushes the water out. More recently, transparent enclosures around the area to be welded are being used. The welder/diver then welds using several MMA electrodes in turn. They work from outside the chamber and the electrodes are already positioned through a flexible port in advance. The enclosures are made for every joint needing to be welded, and this process costs much less than the conventional method of making a large chamber.
There are many jobs available world wide for those who want to have a career in underwater welding. Some welders work on oil platforms or on pipelines that transport oil. Others work on securing docks or even repair ships while at sea or in port. There are also opportunities in the military for underwater welders. Many welder-divers see underwater welding as a stepping stone to other careers. Some move on to become instructors while others take other welding jobs in industry. The possibilities are nearly endless. Jobs that are more risky tend to pay the most.
There is a great deal of risk involved with underwater welding. The biggest risk is electrical shocks. There is also the chance of explosions in some kinds of underwater welding, particularly in applications where both hydrogen and oxygen are used and pockets of gas form. The other big risk is that if a welder-diver comes up to the surface too quickly, they can get nitrogen bubbles in their blood. This is called “the bends” and can be potentially fatal. There are precautions that can be taken to minimize the risks in all areas and many welder-divers never have a problem.