Many people are surprised when they hear of underwater welding because they only know of the welding that occurs on dry land, which is associated with high current electricity. So, how does underwater welding work exactly? How do the welders avoid electrocution? Moreover, how much does an underwater welder make annually?
This article demystifies under water welding, also known as hyperbaric welding; which is currently one of the best paying careers. Read on to know what risks are involved in underwater welding, how they can be mitigated, and why you should not be afraid to take a course and pursue this wonderful career.
What Is Underwater Welding/Hyperbaric Welding?
Underwater welding uses the same tools and techniques as normal welding on dry land. The only difference is that it is performed underwater, which means that some additional equipment is needed to shield the welder from electric shock and prevent water from rapidly cooling the welded surface.
Hyperbaric welding is a process usually used underwater, preforming welds at elevated pressures. This involved both wet and dry welding.
An underwater welder also needs to have diving skills in addition to welding skills to ensure he or she can weld in the underwater environment. Diving skills help the welders know what they need to do to survive the high-pressure conditions of below the sea.
You might be surprised to know that underwater welding has existed for quite a long time. The cdiver net news website says underwater welding was introduced in the 1930s. Underwater welding has been used to repair bridges and sea vessels like ships and submarines.
Modern underwater divers can work either offshore or in inland underwater environments. Offshore welders work on small ships, oilrigs, and pipelines that run underwater while inland welders perform welding jobs on dams and bridges.
Sometimes underwater divers can be called to do repairs on delicate equipment such as nuclear power plants. The Union of Concerned Scientists website says that nuclear plants are located underwater and near large water bodies for cooling and to limit radiation exposure to humans.
How Much Does Underwater Welders Make?
Underwater welding comes with its fair share of risks. As a result, underwater divers are compensated handsomely for the risks that they take when doing the job.
According to the PayScale website, an underwater welder can make anywhere between $17 and $41 per hour depending on his or her skill level. The average welder earns about $25 per hour. This translates to an annual salary of about $60,000.
What Is The Nature Of The Job As An Undersea Welder?
The nature of the job requires lots of travel since the welders work on site. You can work long hours as an underwater welder since the job demands that you see it through to completion once you have started on a contract.
Due to the delicate nature of the job and the risks involved, companies prefer hiring experienced underwater welders. As a beginner, therefore, you have the option of working under an experienced welder as an apprentice to gain some experience before you can venture out on your own.
Types Of Underwater Welding
Underwater welding can be done in a dry environment using hyperbaric chamber technology that protects the welder and the surface to be welded from water. This is known as dry welding and requires some expensive equipment to accomplish.
When the hyperbaric welding chamber cannot be accessed, welders resort to wet welding where welding is done without any shield from water. This is limited by the severity of the work that needs to be done and how accessible the surface that needs welding is.
This means that welders have to survey the work that needs to be done thoroughly before they choose the method of welding to use.
Wet welding is done without any dry chambers. The most common method used in wet welding is shielded metal arch welding where welds are created using a rod of electrolyte that is heated by an electric current. This method is cheap yet effective, making it the go to method for most companies.
Gases are produced when the shield material that surrounds the filler material is melted. The gases come out in form of many bubbles that form a shield between the surface that is being welded and the point of the filler material. These bubbles protect the welder from being electrocuted when they are doing the welds. Electric current used for welding underwater is also supplied in form of direct current (DC) as opposed to alternating current (AC), which further prevents the welder from being electrocuted.
You, however, need to clean the surfaces that need welding and the electrode thoroughly prior to the welding to allow maximum contact.
The main problem associated with wet welding results from the gas bubbles produced when the electrode is melted. The bubbles cause problems by blocking the surface you are welding. To ensure you do a clean job, be sure to check the surface carefully before you start welding.
Other welding techniques can be used for wet welding. These include flux-cored welding, which uses a tabular wire filled with flux to weld surfaces, and friction welding, which uses heat from friction to join two metal pieces together and no external heat source.
This video from Jonathan Noiles YouTube page shows an example of how labor intensive underwater welding can get. Check it out before reading the rest of the article.
Dry welding involves the creation of a dry hyperbaric chamber from where the welding is performed. Water is then sucked out of the chamber and replaced with helium and oxygen gases to aid combustion. The underwater environment also requires that pressure in the chamber be regulated to match the pressure outside the chamber. This prevents the chamber from collapsing and protects the welders from suffering decompression sickness.
Welders have 4 types of dry welding options to pick from: habitat welding, dry spot welding, pressure welding, and dry chamber welding.
Habitat welding involves creating large pressurized chambers that could accommodate one or two individuals. Air is then pumped continuously in and out of the chamber to allow the welders inside to breathe. The chambers created in habitat welding provide a safe working environment for the welders since the continuous flow of air in and out of the chamber does not allow the buildup of toxic gases from the welds being done.
Dry Spot Welding
Dry spot welding involves creation of small chambers around the area that requires to be welded that can fit the welding equipment. One important precaution that you should always take when doing dry spot welding is to ensure that an airtight seal is maintained around the place you are welding. While placing the welding equipment, you should be careful not to leave any gaps where water can leak into the chamber.
As the name suggests, this method uses high mechanical pressure to join two parts into a single piece. Pressure welding is a broad term that covers many welding techniques such as explosion welding, friction stir welding, and diffusion welding. Friction stir welding is the most popular pressure welding method used today.
Dry Chamber Welding
Dry chamber welding has chambers that fit about half of an adult's body size. Welders can access the chamber from underneath and must have diving gear over the entire body. The chamber in most cases covers only the torso of the welder.
Methods Used In Dry Welding
Flux-cored welding- uses a tabular wire filled with flux and heated with electric current
Shielded metal arc welding- uses an electrolyte heated by an electric current.
Tungsten arc welding- uses a tungsten arc to heat up an additional metal rod to join two metal pieces
Gas metal arc welding- uses gas to heat up filler metal rods to melting point to join to metal pieces
Plasma arc welding- uses hot ionized gases to heat up two metal pieces until they melt to join them
Risks and Dangers Of Underwater Welding
When doing welding jobs under water, you expose yourself to more risks as compared to welding on the surface. The long hours spent underwater, for instance, could cause harm to the human body. Underwater welders even have a high fatality rate during the job, which stands at 15%. This is caused by the nature of the job.
To begin with, the welding jobs are located in remote locations where emergency response services are not available. Even if you were to raise alarm when working underwater, first responders would have arrive too late to rescue you.
Secondly, underwater welders face higher risks of electrocution. To avoid being electrocuted, ensure that you only use welding equipment that is designed for working underwater. To be safe, always check the equipment for cracks that might allow water inside before you go for the job.
Being submerged in water for a long time exposes the welder to Hypothermia. According to an article posted on The Scientific American paper, the human body suffers from hypothermia when immersed to cold water for a long time. The article continues to say that the colder the water, the faster hypothermia sets in.
As such, make sure you don't spend too much time under the water when welding. You can plan the jobs so that you can do it in shifts that allow you to get out of the cold water for some time. If you plan on working for several hours, be sure to don an insulated rubber suit to keep you warm.
The underwater environment has higher pressure as compared to the ground. This difference is due to the water that is above you when you have dived to the underwater environment. It is important to know that staying in that high-pressure environment might cause hearing impairment to some individuals.
You have to ensure that you are fit physically before taking a welding job underwater. The tough conditions can take a toll on your body, especially if you have any underlying medical condition. This means that you have to be ready to take a fitness test regularly if you will be working underwater. If the test results indicate that you are not fit enough to go underwater, do not take any chances. It is better to be safe than sorry.
Underwater divers are also prone to attacks by sea creatures, such as sharks and whales, when working in deep waters. Even the other marine life that is not harmful might distract the welder and lead to injury or a poor welding job.
From this article, you can see the risks that come with working underwater. Although such issues might seem scary, they can be mitigated by following simple rules. For instance, ensure that you have all the necessary protective gear anytime you are working underwater. Moreover, never work alone and always maintain constant communication with your team.
In case of a problem, raise alarm immediately. The risks involved are well compensated for when you have the necessary skills to do a welding job underwater. You can check online for institutions that offer training on underwater welding and begin your journey to one of the most lucrative careers.